System and device with laser array illumination

ABSTRACT

A system includes: a heat sink module with a plurality of first through-holes linking its top and bottom surfaces and a plurality of grooves on the bottom surface, wherein each groove passes through a respective sequence of the first through-holes; and a driving circuit module with a plurality of conductive connectors and electrical driving surfaces that are disposed substantially perpendicular to the top and bottom surfaces of the heat sink module, wherein each conductive connector lies partially within a respective groove in the bottom surface of the heat sink module, the conductive connectors include internal connectors that each links at least two of the first through-holes in a respective sequence of first through-holes, and external connectors that each links at least one of the first through-holes in a respective sequence of first through-holes to an electrical driving surfaces of the driving circuit module.

RELATED APPLICATIONS

This application is a continuation of PCT Application No.PCT/CN2016/098763, filed Sep. 12, 2016, the content of which isincorporated by reference herein in its entirety.

FIELD

The present disclosure relates to illumination systems, in particular,illumination systems that include laser arrays as light sources.

BACKGROUND

Systems and devices with laser array illumination are widely applicable,e.g., in image projection, lighting, advertisement display, etc. in bothlarge scale public viewing settings and in medium or small indoorsettings.

When constructing systems and devices with laser array illumination,special attention is required to ensure optical alignment, sufficientillumination power, and proper device cooling during normal operation.In addition, electronic driving circuit control of the individual lasercomponents is also needed. When a relatively low cost and compact systemis desired, meeting such design requirements becomes particularlychallenging.

In general, many systems and devices that use laser array illuminationemploy laser arrays of semiconductor diode lasers or diode-pumped solidstate lasers (DPSSLs) as their light sources. The semiconductor diodelasers are typically in a TO-CAN packaged form and are arranged in agrid pattern within a support substrate structure that includesintegrated driving and cooling layers. The diode-pumped solid statelasers may be packaged in individual enclosures with independent coolingand driving systems and then mounted onto a common support structureaccording to a desired grid pattern. The two types of lasers havedifferent characteristics and advantages, and individualized designs areneeded to better utilize them in systems and devices for laser arrayillumination.

SUMMARY

A method of assembling a diode-pumped solid state laser module,includes: obtaining a heat sink module, wherein the heat sink moduleincludes a first surface, a second surface opposite to the firstsurface, and at least a first through-hole linking the first surface andthe second surface; bonding the second surface of the heat sink moduleonto a cooling surface, wherein the cooling surface and the firstthrough-hole form a first cavity with a top opening in the first surfaceof the heat sink module and a bottom seal in the cooling surface;bonding at least a first component of the diode-pumped solid state lasermodule to the first surface of the heat sink module such that the firstcomponent is in thermal contact with the first surface of the heat sinkmodule; after bonding the second surface of the heat sink module ontothe cooling surface to form the first cavity, partially filling athermal conductive medium into the first cavity such that the thermalconductive medium is in thermal contact with the cooling surface in thefirst cavity; inserting a second component of the diode-pumped solidstate laser module into the first cavity, wherein the second componentincludes a upper portion and a lower portion supporting the upperportion, and wherein after the insertion, the lower portion of thesecond component deforms the thermal conductive medium inside the firstcavity and achieves thermal contact with the cooling surface through thedeformed thermal conductive medium; and affixing the second component tothe heat sink module.

A diode-pumped solid state laser module includes: a heat sink module,wherein the heat sink module includes a first surface, a second surfaceopposite to the first surface, and at least a first through-hole linkingthe first surface and the second surface; a cooling module, wherein thecooling module includes a cooling surface and a thermoelectric coolingsystem, and a heat dissipater, wherein the second surface of the heatsink module is bonded onto the cooling surface of the cooling module,and wherein the cooling surface of the cooling module and the firstthrough-hole in the heat sink module form a first cavity with a topopening in the first surface of the heat sink module and a bottom sealin the cooling surface of the cooling module; thermal conductive mediumpartially filled within the first cavity formed by the cooling surfaceof the cooling module and the first through-hole in the heat sinkmodule; a first component of the diode-pumped solid state laser module,wherein the first component of the diode-pumped solid state laser isbonded to the first surface of the heat sink module such that the firstcomponent is in thermal contact with the first surface of the heat sinkmodule; and a second component of the diode-pumped solid state lasermodule, wherein the second component of the diode-pumped solid statelaser module is partially inserted into the first cavity formed by thecooling surface of the cooling module and the first through-hole in theheat sink module, wherein the second component includes a upper portionand a lower portion supporting the upper portion, wherein the lowerportion of the second component deforms the thermal conductive mediuminside the first cavity and achieves thermal contact with the coolingsurface through the deformed thermal conductive medium, and wherein thesecond component is affixed to the heat sink module.

A system (e.g., a laser diode array module or a component thereof)includes: a heat sink module, wherein: the heat sink module includes arespective top surface, a respective bottom surface opposite to therespective top surface of the heat sink module, and a plurality of firststepped through-holes linking the respective top surface and therespective bottom surface of the heat sink module, each first steppedthrough-hole has a respective cylindrical upper portion and a respectivecylindrical lower portion that is narrower than the respectivecylindrical upper portion of said each first stepped through-hole, therespective cylindrical upper portion and the respective cylindricallower portion of said each first stepped through-hole are joined by arespective first ring-shaped surface, and the respective bottom surfaceof heat sink module includes a plurality of grooves, wherein each groovepasses through the respective lower portions of a respective sequence offirst stepped through-holes among the plurality of first steppedthrough-holes in the heat-sink module; and a driving circuit module,wherein: the driving circuit module includes a plurality of conductivelead connectors, and one or more electrical driving surfaces that aredisposed substantially perpendicular to the respective top and bottomsurfaces of the heat sink module, each conductive lead connector lies atleast partially within a respective one of the plurality of grooves inthe respective bottom surface of the heat sink module, the plurality ofconductive lead connectors includes a set of internal lead connectorsand a set of external lead connectors, each of the set of internal leadconnectors links at least two of the first stepped through-holes in therespective sequence of first stepped through-holes passed by therespective one of the plurality of grooves in the respective bottomsurface of the heat sink module, and each of the set of external leadconnectors links at least one of the first stepped through-holes in therespective sequence of first stepped through-holes passed by therespective one of the plurality of grooves in the respective bottomsurface of the heat sink module to at least one of the one or moreelectrical driving surfaces of the driving circuit module that aredisposed substantially perpendicular to the respective top and bottomsurfaces of the heat sink module.

A system (e.g., a double-sided laser diode array module or a componentthereof) comprises: a cooling module having a first side and a secondside opposite the first side, and a cooling mechanism disposed betweenthe first side and the second side of the cooling module; a first heatsink module having a respective top surface, a respective bottom surfaceopposite the respective top surface of the first heat sink module, and arespective plurality of first through-holes linking the respective topand bottom surfaces of the first heat sink module, wherein therespective bottom surface of the heat sink module is disposed next tothe first side of the cooling module; a first plurality of laser diodes,wherein each of the first plurality of laser diodes includes arespective diode body, a respective set of conductive leads, and arespective support plate between the respective diode body and therespective set of conductive leads, wherein each of the first pluralityof laser diodes is disposed at least partially within a respective oneof the respective plurality of first through-holes in the first heatsink module with the respective diode body disposed next to therespective top surface of the first heat sink module and the respectiveset of conductive leads disposed next to the bottom surface of the firstheat sink module; a first driving circuit module including a respectiveplurality of conductive lead connectors and respective one or moreelectrical driving surfaces, wherein the respective one or moreelectrical driving surfaces of the first driving circuit module aredisposed substantially perpendicular to the respective top and bottomsurfaces of the first heat sink module, and wherein the respectiveplurality of conductive lead connectors of the first driving circuitmodule connect the respective set of conductive leads of the firstplurality of laser diodes to the respective one or more electricaldriving surfaces of the first driving circuit module; a second heat sinkmodule having a respective top surface, a respective bottom surfaceopposite the respective top surface of the second heat sink module, anda respective plurality of second through-holes linking the respectivetop and bottom surfaces of the second heat sink module, wherein therespective bottom surface of the heat sink module is disposed next tothe second side of the cooling module; a second plurality of laserdiodes, wherein each of the second plurality of laser diodes includes arespective diode body, a respective set of conductive leads, and arespective support plate between the respective diode body and therespective set of conductive leads, wherein each of the second pluralityof laser diodes is disposed at least partially within a respective oneof the respective plurality of second through-holes in the second heatsink module with the respective diode body disposed next to therespective top surface of the second heat sink module and the respectiveset of conductive leads disposed next to the bottom surface of thesecond heat sink module; and a second driving circuit module including arespective plurality of conductive lead connectors and respective one ormore electrical driving surfaces, wherein the respective one or moreelectrical driving surfaces of the second driving circuit module aredisposed substantially perpendicular to the respective top and bottomsurfaces of the second heat sink module, and wherein the respectiveplurality of conductive lead connectors of the second driving circuitmodule connect the respective set of conductive leads of the secondplurality of laser diodes to the respective one or more electricaldriving surfaces of the second driving circuit module.

A system comprises: a heat sink module having a respective top surface,a respective bottom surface opposite the respective top surface of theheat sink module, a first plurality of first through-holes linking therespective top and bottom surfaces of the heat sink module, a secondplurality of second through-holes linking the respective top and bottomsurfaces of the heat sink module, wherein the first plurality of firstthrough-holes are arranged according to a first grid pattern and thesecond plurality of second through-holes are arranged according to asecond grid pattern, and wherein the first grid pattern and the secondgrid pattern are offset from each other; a first plurality of laserdiodes, wherein each of the first plurality of laser diodes includes arespective diode body, a respective set of conductive leads, and arespective support plate between the respective diode body and therespective set of conductive leads, wherein each of the first pluralityof laser diodes is disposed at least partially within a respective oneof the first plurality of first through-holes in the heat sink modulewith the respective diode body disposed next to the respective topsurface of the heat sink module and the respective set of conductiveleads disposed next to the respective bottom surface of the heat sinkmodule; a second plurality of laser diodes, wherein each of the secondplurality of laser diodes includes a respective diode body, a respectiveset of conductive leads, and a respective support plate between therespective diode body and the respective set of conductive leads,wherein each of the second plurality of laser diodes is disposed atleast partially within a respective one of the second plurality ofsecond through-holes in the heat sink module with the respective diodebody disposed next to the respective bottom surface of the heat sinkmodule and the respective set of conductive leads disposed next to therespective top surface of the heat sink module; and a driving circuitmodule including a respective plurality of conductive lead connectorsand respective one or more electrical driving surfaces, wherein therespective one or more electrical driving surfaces of the drivingcircuit module are disposed substantially perpendicular to therespective top and bottom surfaces of the heat sink module, wherein afirst subset of conductive lead connectors among the respectiveplurality of conductive lead connectors of the driving circuit moduleconnect the respective set of conductive leads of the first plurality oflaser diodes to the respective one or more electrical driving surfacesof the driving circuit module, and wherein a second subset of conductivelead connectors among the respective plurality of conductive leadconnectors of the driving circuit module connect the respective set ofconductive leads of the second plurality of laser diodes to therespective one or more electrical driving surfaces of the drivingcircuit module.

A system comprises: a heat sink module, wherein: the heat sink moduleincludes a respective top surface, a respective bottom surface oppositeto the respective top surface of the heat sink module, and a pluralityof first through-holes linking the respective top surface and therespective bottom surface of the heat sink module, and the respectivebottom surface of heat sink module includes a plurality of grooves,wherein each groove passes through the respective lower portions of arespective sequence of first through-holes among the plurality of firstthrough-holes in the heat-sink module; and a driving circuit module,wherein: the driving circuit module includes a plurality of conductivelead connectors, and one or more electrical driving surfaces that aredisposed substantially perpendicular to the respective top and bottomsurfaces of the heat sink module, each conductive lead connector lies atleast partially within a respective one of the plurality of grooves inthe respective bottom surface of the heat sink module, the plurality ofconductive lead connectors include a set of internal lead connectors anda set of external lead connectors, each of the set of internal leadconnectors links at least two of the first through-holes in therespective sequence of first through-holes passed by the respective oneof the plurality of grooves in the respective bottom surface of the heatsink module, and each of the set of external lead connectors links atleast one of the first through-holes in the respective sequence of firstthrough-holes passed by the respective one of the plurality of groovesin the respective bottom surface of the heat sink module to at least oneof the one or more electrical driving surfaces of the driving circuitmodule that are disposed substantially perpendicular to the respectivetop and bottom surfaces of the heat sink module.

Other embodiments and advantages are apparent to those skilled in theart in light of the descriptions and drawings in this specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a side view schematic of an exemplary conventionaldiode-pumped solid state laser module.

FIG. 1B is a side view schematic of an exemplary diode-pumped solidstate laser module in accordance with some embodiments.

FIG. 1C illustrates an exemplary heat sink module in accordance withsome embodiments.

FIG. 1D illustrates three exemplary laser crystal components inaccordance with some embodiments.

FIG. 1E is a side view schematic of a diode-pumped solid state lasermodule in accordance with some embodiments.

FIG. 1F is a flowchart of an exemplary method 60 for assembling adiode-pumped solid state laser module (e.g., the diode-pumped solidstate lasers 20 and 30 in FIGS. 1B and 1E), in accordance with someembodiments.

FIG. 2A illustrates schematics of an exemplary laser diode.

FIG. 2B illustrates the top and bottom views of an exemplary laser arraymodule in accordance with some embodiments.

FIG. 2C illustrates an exploded view of the exemplary laser array modulein FIG. 2B.

FIG. 2D illustrates a lens array substrate layer in the exemplary laserarray module shown in FIGS. 2B and 2C, in accordance with someembodiments.

FIG. 2E illustrates the top and bottom views of a heat sink module inthe exemplary laser array module shown in FIGS. 2B and 2C, in accordancewith some embodiments.

FIG. 2F illustrates schematics of an L-shaped conductive lead connectorand a U-shaped conductive lead connector used in the exemplary laserarray module shown in FIGS. 2B and 2C, in accordance with someembodiments.

FIG. 2G illustrates the top and bottom views of an exemplary laser diodearray in the exemplary laser array module shown in FIGS. 2B and 2C, inaccordance with some embodiments.

FIG. 2H shows the bottom and side views of the connections between thelaser diodes and the conductive lead connectors in the exemplary laserarray module shown in FIGS. 2B and 2C, in accordance with someembodiments.

FIG. 2I shows the top and bottom views of another exemplary laser diodearray in the exemplary laser array module shown in FIGS. 2B and 2C, inaccordance with some embodiments.

FIG. 2J illustrates an exemplary arrangement of the conductive leadconnectors based on the arrangement of the laser diodes in FIG. 2I, inaccordance with some embodiments.

FIG. 2K illustrates an exemplary groove pattern in the bottom surface ofthe heat sink module based on the arrangement of the conductive leadconnectors shown in FIG. 2J, in accordance with some embodiments.

FIG. 2L illustrates the top and bottom views of another exemplary laserarray module in accordance with some embodiments.

FIG. 2M illustrates an exploded view of the exemplary laser array modulein FIG. 2L.

FIG. 2N illustrates the heat sink module in the exemplary laser arraymodule shown in FIGS. 2L and 2M, in accordance with some embodiments.

FIG. 2O illustrates the top and bottom views of another heat sink modulein accordance with some embodiments.

FIG. 2P illustrates the top and bottom views of another heat sink modulein accordance with some embodiments.

FIG. 2Q illustrates the top and bottom views of another exemplary laserarray module in accordance with some embodiments.

FIG. 2R illustrates an exemplary double-sided laser array module inaccordance with some embodiments.

FIG. 2S illustrates the top and bottom views of another heat sink modulein accordance with some embodiments.

FIG. 2T illustrates another exemplary double-sided laser array module inaccordance with some embodiments.

FIG. 2U illustrates the cross-sectional views of the exemplarydouble-sided laser array module shown in FIG. 2T.

FIG. 2V illustrates another exemplary double-sided laser array module inaccordance with some embodiments.

FIG. 2W illustrates the cross-sectional views of the exemplarydouble-sided laser array module shown in FIG. 2V.

FIG. 2X illustrates the structure an exemplary lens array module withlenses supported by two adjacent substrate layers, in accordance withsome embodiments.

FIG. 2Y illustrates the structure of an exemplary lens array module withintegrated lens domes on a substrate layer, in accordance with someembodiments.

FIG. 2Z illustrates the top and bottom views of another exemplary heatsink module in accordance with some embodiments.

FIGS. 2AA-2AB illustrate components of the exemplary heat sink moduleshown in FIG. 2Z in accordance with some embodiments.

FIG. 2AC illustrates the top and bottom views of another exemplary heatsink module in accordance with some embodiments.

FIG. 2AD illustrates the top and bottom views of another exemplary heatsink module in accordance with some embodiments.

FIGS. 2AE-2AG illustrate components and internal structures of theexemplary heat sink module shown in FIG. 2AD in accordance with someembodiments.

FIGS. 2AH-2AI illustrate exploded views of two exemplary laser arraymodules that are variations of the laser array module shown in FIG. 2C,in accordance with some embodiments.

FIGS. 2AJ-2AK illustrate an exemplary lens array substrate layer that isa variation of the lens array substrate layer shown in FIG. 2D, inaccordance with some embodiments.

FIG. 2AL illustrates an exemplary heat sink module that is a variationof the exemplary heat sink module shown in FIG. 2E, in accordance withsome embodiments.

FIGS. 2AM-2AS illustrate exemplary laser array modules that arevariations of the laser array module shown in FIG. 2H-(2), in accordancewith some embodiments.

FIGS. 2AT-2AU illustrate exploded views of two exemplary laser arraymodules that are variations of the laser array module shown in FIG. 2M,in accordance with some embodiments.

FIG. 2AV illustrates an exemplary integrated heat sink/cooling modulethat is a variation of the integrated heat sink/cooling module shown inFIG. 2N, in accordance with some embodiments.

FIG. 2AW illustrates an exemplary integrated heat sink/cooling modulethat is a variation of the integrated heat sink/cooling module shown inFIG. 2O, in accordance with some embodiments.

FIG. 2AX illustrates an exemplary integrated heat sink/cooling modulethat is a variation of the integrated heat sink/cooling module shown inFIG. 2P, in accordance with some embodiments.

FIG. 2AY illustrates an exemplary lens array module that is a variationof the lens array module shown in FIG. 2X, in accordance with someembodiments.

FIG. 2AZ illustrates an exemplary heat sink/cooling module that is avariation of the integrated heat sink/cooling module shown in FIG. 2Z,in accordance with some embodiments.

FIG. 2BA illustrates an exemplary integrated heat sink/cooling modulethat is a variation of the integrated heat sink/cooling module shown inFIG. 2AA, in accordance with some embodiments.

FIG. 2BB illustrates an exemplary integrated heat sink/cooling modulethat is a variation of the integrated heat sink/cooling module shown inFIG. 2AC, in accordance with some embodiments.

FIG. 2BC illustrates an exemplary integrated heat sink/cooling modulethat is a variation of the integrated heat sink/cooling module shown inFIG. 2AD, in accordance with some embodiments.

FIG. 2BD illustrates an exemplary heat sink element that is a variationof the heat sink element shown in FIG. 2AF-(2), in accordance with someembodiments.

FIG. 2BE illustrates an exemplary integrated heat sink/cooling modulethat is a variation of the integrated heat sink/cooling module shown inFIG. 2AG, in accordance with some embodiments.

Like reference numerals refer to corresponding parts throughout thedrawings.

DETAILED DESCRIPTION

As introduced in the Background section, in addition to diode lasers,diode-pumped solid state lasers can also be used in laser lighting,laser imaging, and laser display applications. Typically, a diode-pumpedsolid state laser has a much higher power output than a semiconductordiode laser. For example, the output of a typical diode-pumped solidstate laser may be a few times to dozens of times that of a typicalsemiconductor diode laser. The higher output of diode-pumped solid statelaser can sometimes lead to a reduction in the number of lasers requiredin a device, and possibly a smaller device footprint and simpler drivingcontrols. In addition, diode-pumped solid state lasers also enjoy ahigher electricity-to-light conversion efficiency among different typesof solid state lasers.

In general, a diode-pumped solid state laser includes a diode laserchip, and one or more laser crystals (e.g., including one or more lasingcrystals, and/or one or more non-linear frequency conversion crystals).Common examples of lasing crystals (also referred to as lasing medium)include Neodymium-doped Yttrium Aluminium Garnet (Nd:YAG),Neodymium-doped Yttrium Orthovanadate (Nd:YVO4), Neodymium:GadoliniumVanadate (Nd:GdVO4), etc. Common examples of the non-linear frequencyconversion crystals include Lithium Triborate (LBO), Potassium TitanylPhosphate (KTP), Magnesium-doped Periodically Poled Lithium Niobate(MgO:PPLN), Periodically Poled Lithium Tantalate (PPLT) and PeriodicallyPoled Stoichiometric Lithium Tantalate (PPSLT).

FIG. 1A is a side view schematic of an exemplary conventionaldiode-pumped solid state laser 10. The diode-pumped solid state laser 10includes a resonance cavity. Typically, the output wavelengths of thediode-pumped solid state laser 10 can be 671 nm, 532 nm, 456 nm, etc. Asshown in FIG. 1A, the diode-pumped solid state laser 10 includes a diodelaser chip 8, a convergent lens 9, a lasing crystal 11, a non-linearfrequency conversion crystal 12, an output mirror 14, and varioussupport structures for the above components. For example, the diodelaser chip 8 is affixed onto an onboard heat sink 26, forming arespective laser component. The heat created during the operation of thediode laser chip 8 is transmitted to the onboard heat sink 26. In someembodiments, the convergent lens 9 is affixed to a lens seat 27, forminga respective laser component. The lasing crystal 11 is affixed to acrystal seat 28, forming a respective laser component (e.g., a lasercrystal module). Thermal conductive medium 34 is filled between thelasing crystal 11 and the crystal seat 28 to improve thermal contactbetween the lasing crystal 11 and the crystal seat 28. The heat createdduring the operation of the lasing crystal 11 is transmitted to thecrystal seat 28 through the thermal conductive medium 34. The non-linearfrequency conversion crystal 12 is affixed to the crystal seat 29,forming a respective laser component. Thermal conductive medium 34 isfilled between the non-linear frequency conversion crystal 12 and thecrystal seat 29 to improve thermal contact between the non-linearfrequency conversion crystal 12 and the crystal seat 29. The heatcreated during the operation of the non-linear frequency conversioncrystal 12 is transmitted to the crystal seat 29 through the thermalconductive medium 34. The output mirror 14 of the resonance cavity forthe laser 10 is affixed to a mirror seat 30, forming a respective lasercomponent. Other laser components that have respective upper portionsaffixed to respective lower portions are possible, where the upperportions generate heat during operation, and the heat is transmitted tothe respective lower portions.

In the conventional diode-pumped solid state laser 10, the onboard heatsink 26, the lens seat 27, the crystal seat 28, the crystal seat 29, andthe mirror seat 30 are affixed to a common laser heat sink module 31(e.g., to the top surface of the laser heat sink module 31), withthermal conductive medium 34 filled between the top surface of thecommon laser heat sink module 31 and the various laser components thatare affixed to the laser heat sink 31. During operation, the heatcreated in the various laser components are transmitted to the laserheat sink module 31 from the lower portions of the various lasercomponents (e.g., from the onboard heat sink 26, the lens seat 27, thecrystal seat 28, the crystal seat 29, and the mirror seat 30 to thelaser heat sink module 31). In addition, the laser heat sink module 31is rigid and maintains the relative positions of the various componentsthat are affixed to the top surface of the laser heat sink module 31,thereby maintaining the stability of the optical path within thediode-pumped solid state laser 10 and ensuring the stable operationthereof.

On the other side (e.g., the bottom surface) of the laser heat sinkmodule 31, the laser heat sink module 31 is in thermal contact with thecooling surface of a thermoelectric cooling device 32 (e.g., athermoelectric cooler (TEC)). The heating surface of the thermoelectriccooling device 32 is opposite to the cooling surface of thethermoelectric cooling device 32, and is connected to a heat dissipater33. Thermal conductive medium 34 is filled between the bottom surface ofthe laser heat sink module 31 and the cooling surface of thethermoelectric cooling device 32, and between the heating surface of thethermoelectric cooling device 32 and the heat dissipater 33.

The onboard heat sink 26, the crystal seat 28, the crystal seat 29, thelaser heat sink module 31 can be made from conductive or insulatingthermal conductive materials, such as copper, aluminum nitrate ceramics,etc. The lens seat 27 and the mirror seat 30 can be made from conductorsor insulators, such as glass, metals, etc. The heat dissipater 33 canutilize gas or liquid cooling. The thermal conductive medium 34 can bemade from conductors or insulators, such as indium foil, conductivesilicone, conductive silver adhesive, and/or phase change thermalconducting materials, etc.

In a conventional diode-pumped solid state laser, such as thediode-pumped solid state laser 10 shown in FIG. 1A, the laser chip, thevarious laser crystals, lenses, and mirrors individually transmit heatto one or more respective heat sinks and seats, and realize thermalexchange with the TEC through these respective heat sinks and seats. Inaddition, the heat sinks and seats are used to affix the laser chip andthe various laser crystals, lenses, and mirrors in order to maintainstability of the optical path in the laser. Some drawbacks involved inthis conventional configuration include thermal interference of thevarious components of the laser, and inefficient heat transfer due tothe thermal resistance existing between the various componentinterfaces.

An improved diode-pumped solid state laser as disclosed herein allowssome components (e.g., the laser component including the laser chip andits onboard heat sink, and the laser components including variouscrystals with their respective crystal seats, etc.) of the laser to beaffixed directly on the cooling surface of the TEC to achieve directthermal contact with the TEC and exchange heat directly with the TEC,thereby reducing the thermal interference between these components andother laser components that are not directly affixed to the TEC, andimproving the efficiency of the heat dissipation.

In the example diode-pumped solid state laser 10 shown in FIG. 1A, theonboard heat sink 26, the crystal seat 28 and the crystal seat 29 are inthermal contact with the same laser heat sink module 31. Because thediode laser chip 8 is the component that produces the most heat in thelaser 10, most of the heat transmitted to the laser heat sink 31 is fromthe onboard heat sink 26. Consequently, the lasing crystal 11 and thenon-linear frequency conversion crystal 12 will be thermally affected bythe heat generated by the diode laser chip 8. The operation stability ofthe laser chip 8 greatly depends on the operation temperature. Theoptical properties of the lasing crystal 11 and the non-linear frequencyconversion crystal 12 also depend on efficient thermal exchange with theTEC 32.

As shown in FIG. 1B, an exemplary diode-pumped solid state laser 20 isan improvement over the conventional diode-pumped solid state laser 10,in accordance with some embodiments. For easy illustration, thediode-pumped solid state laser 20 is substantially similar to theconventional diode-pumped solid state laser 10, except for theconfiguration of the common laser heat sink and the positions of thelaser crystal modules relative to the common laser heat sink. As shownin FIG. 1B, instead of the common laser heat sink 31, a new laser heatsink 35 is used between the various laser components (e.g., laser chip 8with the onboard heat sink 26, the lens 9 with the lens seat 27, thelasing crystal 11 with its crystal seat, the non-linear frequencyconversion crystal 12 with its crystal seat, and the output mirror 14with the mirror seat 30) and the TEC 32. In some embodiments, the newlaser heat sink module 35 is substantially similar to the conventionallaser heat sink module 31, but with at least one through-hole (e.g., twothrough-holes 38 and 39) created between its top surface and its bottomsurface, as shown in FIG. 1B.

As shown in the FIG. 1B, a crystal seat 36 (e.g., a cylindrical crystalseat) and a crystal seat 37 are placed within the through-holes 38 and39, respectively. The crystal seats 36 and 37 are placed as close to thecooling surface of the TEC 32 as possible, with thermal conductivemedium 40 (e.g., thermal conductive medium 40 can be the same as thermalconductive medium 34 or different from thermal conductive medium 34)applied between the cooling surface of the TEC 32 and the bottomsurfaces of the crystal seats 36 and 37. In addition, the crystal seats36 and 37 are affixed to the laser heat sink 35 (e.g., the crystal seats36 and 37 are glued to the top surface of the laser heat sink 35 withglue dots 41 around one or more points around the gap between the sidesof the crystal seats 36 and 37 and the inner surfaces of thethrough-holes 38 and 39 or the top surface of the laser heat sink module35). Other methods of affixing the crystal seats to the laser heat sink(e.g., using screws or other mechanical fastening mechanisms) arepossible. During operation, heat is transmitted from the lasing crystal11 to the crystal seat 36 (e.g., through the thermal conductive medium34), and then to the cooling surface of the TEC 32 (e.g., through thethermal conductive medium 40); and heat is transmitted from thenon-linear frequency conversion crystal 12 to the crystal seat 37 (e.g.,through the thermal conductive medium 34), and then to the coolingsurface of the TEC 32 (e.g., through the thermal conductive medium 40).The heat generated by the laser chip 8 is transmitted to the onboardheat sink 26 and then from the onboard heat sink 26 to the laser heatsink 35. Since the crystal seats 36 and 37 are not in direct thermalcontact with the laser heat sink module 35, the heat generated by thelaser chip 8 does not greatly impact the operating temperatures of thelasing crystal 11 and the non-linear frequency conversion crystal 12,thereby improving the operation stability of these laser crystals.

FIG. 1C illustrates an exemplary laser heat sink 35 with two cylindricalthrough-holes 38 and 39 going from the top surface to the bottom surfaceof the laser heat sink module 35 in accordance with some embodiments. Insome embodiments, additional through-holes may be present in the laserheat sink module 35 to accommodate additional laser components (e.g.,one or more additional mirrors, lenses, and crystals, with respectiveseats and/or heat sinks thereof) in the diode-pumped solid state laser20.

FIG. 1D-(1) illustrates an exemplary lasing crystal 11 affixed to acylindrical laser crystal seat 36, with thermal conductive medium 34applied between the lasing crystal 11 and the laser crystal seat 36, inaccordance with some embodiments. FIG. 1D-(2) illustrates an exemplarynon-linear frequency conversion crystal 12 affixed to a cylindricallaser crystal seat 37, with thermal conductive medium 34 applied betweenthe non-linear frequency conversion crystal 12 and the crystal seat 37,in accordance with some embodiments.

Although the crystal seats 36 and 37 and the through-holes 38 and 39 areshown to be cylindrical with circular cross-sections in FIGS. 1D-(1) and1D-(2), other cross-sectional shapes (e.g., oval, square, rectangular,customized, etc.) are possible in accordance with various embodiments.In general, the cross-sectional shapes of the crystal seats and thecross-sectional shapes of the through-holes are geometrically similar,such that the placement of the crystal seats within the through-holescan be centered easily. In addition, although crystal seats are used inthe examples shown in FIGS. 1B, 1D-(1) and 1D-(2) as the lower portionsof the laser components that are placed in direct contact with thecooling surface of the TEC, a person skilled in the art would understandthat the lower portions of the other types of laser components (e.g., anonboard heat sink of a laser chip, a mirror seat of a mirror, and/or alens seat of a lens, etc.) can also be placed in direct contact with theTEC through respective through-holes created in the common laser heatsink module placed above the TEC. The key is that some laser componentsare placed in indirect thermal contact with the TEC through a commonheat sink module (e.g., the heat sink module 35), while other lasercomponents are placed in direct thermal contact with the TEC throughrespective through-holes created in the common heat sink module. Thisway, thermal interference between the two groups of laser components canbe reduced. In some embodiments, a laser component may be an integratedcomponent with no apparent structural division between its upper andlower portions, and in such cases, the points of affixation to the wallsor upper edges of the through-hole may be considered to be the start ofthe lower portion of the laser component.

In some embodiments, in order to improve the thermal contact between theupper portion (e.g., the lasing crystal 11) and the lower portion (e.g.,the crystal seat 36) of a laser component, and to reduce the thermalresistance between the upper and the lower portions of the lasercomponent, a linear recess is created within the lower portion of thelaser component (e.g., the crystal seat 36) to hold its correspondingupper portion (e.g., the lasing crystal 11). The linear recess runsalong the direction of the optical path in the laser, and thecross-sectional shape of the linear recess matches the shape of theupper portion that would fit within the linear recess. For example, FIG.1D-(3) shows an exemplary crystal seat 42 with a linear recess 43created in its top surface. The linear recess 43 runs through the topportion of the crystal seat 42, such that when a laser crystal (e.g.,the lasing crystal 11) is placed within the recess 43, the optical paththat passes through the laser crystal runs through the recess 43 withoutbeing blocked by the crystal seat 42. As shown in FIG. 1D-(3), thelinear recess 43 is shaped and sized such that its inner surfaces are inthermal contact with the laser crystal not only on the bottom side ofthe laser crystal, but also on two sidewalls of the laser crystal 11,thereby increasing thermal contact area and reducing thermal resistancebetween the lasing crystal 11 and the crystal seat 42.

Although the design in FIG. 1D shows that the upper portion (e.g., thelasing crystal 11) of the laser component within the through-hole (e.g.,the through-hole 38) remains outside of the through-hole, in someembodiments, the entire component can be located within thethrough-hole. For example, in some embodiments, the crystal seat 42shown in FIG. 1D may have a linear recess that is sufficiently deep suchthat the top of the crystal 11 is below the upper surface of the crystalseat 42. In some embodiments, the crystal 11 is still located above thetop surface of the heat sink module (e.g., heat sink module 35), whilein other embodiments, the crystal 11 may optionally be below the topsurface of the heat sink module, provided that the structure of the heatsink module is such that it does not block the optical path of thecrystal 11.

The above designs of the laser heat sink and the crystal seats shown inFIGS. 1B-1D are merely illustrative. In some embodiments, the sameprinciples illustrated through the embodiments shown in FIGS. 1B-1D alsoapply to additional components, such as lenses, lens seats, mirrors,mirror seats, diode chips, and their respective support structuresand/or onboard heat sinks. Furthermore, the number of the differenttypes of components may be more than one in a single laser. For example,there may be more than one laser crystal, non-linear frequencyconversion crystal, lens, mirror, diode chip, etc. in the optical pathof a single laser. In some embodiments, more than one of the laser heatsink modules with through-holes may be used in a laser. For example,FIG. 1E illustrates an exemplary diode-pumped solid state laser 30 inaccordance with some embodiments. The diode-pumped solid state laser 30includes two separate TECs, namely TEC 32-1, and TEC 32-2, where TEC32-1 is in thermal contact with the laser heat sink module 35 and TEC32-2 is in thermal contact with a laser heat sink module 54. As shown inFIG. 1E, both TEC 32-1 and TEC 32-2 are in thermal contact with a heatdissipater 33.

As shown in FIG. 1E, the laser heat sink module 35 includes twothrough-holes 38 and 39, with the crystal seat 36 and the crystal seat37 respectively occupying each of the through-holes 38 and 39 in thelaser heat sink module 35. Similarly, the laser heat sink module 54 alsoincludes two through-holes 52 and 53, with a crystal seat 51 (e.g.,supporting a non-linear frequency conversion crystal 47) and an onboardheat sink 48 (e.g., supporting a diode laser chip 44) respectivelyoccupying each of the through-holes 53 and 52 in the laser heat sinkmodule 54. Other components of the laser, e.g., the laser chip 8 withits onboard heat sink 26, the lens 9 with its lens seat 27, the lasingcrystal 46 with its crystal seat 50, the beam splitter 45 with its seat49 are affixed to the laser heat sink modules 35 and 54, respectively.Other configurations of the diode-pumped solid state lasers arepossible.

FIG. 1F is a flowchart of a method 60 for assembling a diode-pumpedsolid state laser module (e.g., the diode-pumped solid state lasers 20and 30 in FIGS. 1B and 1E), in accordance with some embodiments.

In some embodiments, a heat sink module (e.g., the laser heat sinkmodule 35 in FIGS. 1B, 1C, and 1E, and the laser heat sink module 54 inFIG. 1E) is (62) obtained, where the heat sink module includes a firstsurface (e.g., a top surface), a second surface (e.g., a bottom surface)opposite to the first surface, and at least a first through-hole (e.g.,the through-hole 38 or 39 in FIGS. 1B, 1C, and 1E, and the through-holes52 or 53 in FIG. 1E) linking the first surface and the second surface.

The second surface (e.g., the bottom surface) of the heat sink module(e.g., laser heat sink 35 in FIGS. 1B and 1E, or the laser heat sink 54in FIG. 1E) is (64) bonded onto a cooling surface (e.g., the coolingsurface of the TEC 32 in FIGS. 1B and 1E), where the cooling surface andthe first through-hole form a first cavity (e.g., a cylindrical cavity)with a top opening in the first surface (e.g., top surface) of the heatsink module and a bottom seal in the cooling surface (e.g., the coolingsurface of TEC 32 in FIGS. 1B and 1E).

At least a first component (e.g., the onboard heat sink 26 supportingthe laser chip 8 in FIGS. 1B and 1E, the lens 9 with the lens seat 27 inFIGS. 1B and 1E, the crystal seat 54 supporting the laser crystal 46 inFIG. 1E, and mirror seat 49 supporting the beam splitter 45 in FIG. 1E)of the diode-pumped solid state laser module is bonded (66) to the firstsurface (e.g., top surface) of the heat sink module (e.g., the laserheat sink module 35 in FIG. 1B or 1E, or the laser heat sink 54 in FIG.1E) such that the first component is in thermal contact with the firstsurface of the heat sink module. For example, there is at least onecomponent in the laser that is in direct thermal contact with the topsurface of the laser heat sink, and not in direct thermal contact withthe cooling surface of the TEC.

In some embodiments, the second surface (e.g., the bottom surface) ofthe heat sink module is bonded to the cooling surface of the TEC afterat least the first component (e.g., after some or all of the componentsthat would not be placed into direct contact with the TEC(s) via thethrough-holes created in the heat sink module) is bonded to the firstsurface (e.g., the top surface) of the heat sink module.

After bonding the second surface (e.g., bottom surface) of the heat sinkmodule onto the cooling surface (e.g., the cooling surface of the TEC 32in FIG. 1B or 1E) to form the first cavity (e.g., a cylindrical cavity),a thermal conductive medium (e.g., thermal conductive medium 40) is (68)partially filled into the first cavity such that the thermal conductivemedium is in thermal contact with the cooling surface of the TEC in thefirst cavity.

A second component (e.g., the crystal seat 36 holding the lasing crystal11, the crystal seat 37 holding the non-linear frequency conversioncrystal 12 in FIGS. 1B and 1E, the crystal seat 51 holding thenon-linear frequency conversion crystal 47 in FIG. 1E, or the onboardheat sink 48 holding the diode chip 44 in FIG. 1E) of the diode-pumpedsolid state laser module is (70) inserted into the first cavity, wherethe second component includes a upper portion and a lower portionsupporting the upper portion, and where after the insertion, the lowerportion of the second component deforms the thermal conductive medium(e.g., thermal conductive medium 40) inside the first cavity andachieves thermal contact with the cooling surface of the TEC through thedeformed thermal conductive medium.

The second component (e.g., the lower portion (e.g., the crystal seat36, the crystal seat 37 in FIGS. 1B and 1E, the crystal seat 51 in FIG.1E, or the onboard heat sink 48 in FIG. 1E) of the second component) isaffixed (72) (e.g., glued) to the heat sink module (e.g., the firstsurface (e.g., top surface) of the heat sink module (e.g., the laserheat sink module 35 in FIGS. 1B and 1E, or the laser heat sink module 54in FIG. 1E)).

In some embodiments, after the insertion, the upper portion and at leasta part of the lower portion of the second component remain outside ofthe first cavity, and affixing the second component to the heat sinkmodule includes affixing the lower portion of the second component tothe first surface of the heat sink module.

In some embodiments, the second component of the diode-pumped solidstate laser module includes a laser chip (e.g., the laser chip 44 inFIG. 1E) and an onboard heat sink (e.g., the onboard heat sink 48 inFIG. 1E) that supports the laser chip and that is in thermal contactwith the laser chip, and where the first component of the diode-pumpedsolid state laser module includes a first laser crystal (e.g., thenon-linear frequency conversion crystal 47 in FIG. 1E) and a first lasercrystal seat (e.g., the crystal seat 51 in FIG. 1E) that supports thefirst laser crystal and is in thermal contact with the first lasercrystal. This is illustrated by the right portion of the laser 30 shownin FIG. 1E, for example.

In some embodiments, the first component of the diode-pumped solid statelaser module includes a laser chip (e.g., the laser chip 8 in FIGS. 1Band 1E) and an onboard heat sink (e.g., the onboard heat sink 26 inFIGS. 1B and 1E) that supports the laser chip and that is in thermalcontact with the laser chip, and where the second component of thediode-pumped solid state laser module includes a first laser crystal(e.g., the lasing crystal 11 in FIGS. 1B and 1E, the non-linearfrequency conversion crystals 12 in FIGS. 1B and 1E) and a first lasercrystal seat (e.g., the crystal seat 36 in FIGS. 1B and 1E, the crystalseat 37 in FIGS. 1B and 1E) that supports the first laser crystal and isin thermal contact with the first laser crystal. This is illustrated inFIG. 1B and the left portion of the laser 30 in FIG. 1E, for example.

In some embodiments, the first laser crystal seat (e.g., crystal seat 42in FIG. 1D-(3)) includes a top surface, a bottom surface, and a bodybetween the top surface and bottom surface of the first laser crystalseat, the first laser crystal seat further includes a recess (e.g., alinear recess 43 in FIG. 1D-(3)) in the top surface of the first lasercrystal seat that runs completely through the top surface of the firstlaser crystal seat in a first direction (e.g., the direction of theoptical path in the laser), and where the first laser crystal (e.g.,lasing crystal 11) is disposed within the recess of the first lasercrystal seat and is in thermal contact with two or more inner surfacesof the recess. This is illustrated in FIG. 1D-(3), for example.

In some embodiments, the first cavity is a cylindrical through-hole, andthe first laser crystal seat is a cylindrical body with a linear recessthat runs through the top surface of the cylindrical body. This isillustrated in FIGS. 1C and 1D-(3), for example.

In some embodiments, in accordance with a first optical alignmentrequirement for the first component relative to the second component ofthe diode-pumped solid state laser module, a vertical position by whichthe second component is inserted into the first cavity is adjusted,while the lower portion of the second component remains in thermalcontact with the cooling surface through the deformed thermal conductivemedium, where the adjusting is performed prior to affixing the secondcomponent to the heat sink module.

In some embodiments, the lower portion of the second component isaffixed around the top opening of the first cavity.

In some embodiments, affixing the second component to the heat sinkmodule includes gluing the lower portion of the second component to thefirst surface of the heat sink module around the top opening of thefirst cavity in the first surface of the heat sink module.

In some embodiments, in accordance with a second optical alignmentrequirement for the first component relative to the second component ofthe diode-pumped solid state laser module, a lateral position by whichthe second component is inserted into the first cavity is adjusted,while the lower portion of the second component remains in thermalcontact with the cooling surface through the deformed thermal conductivemedium, where the adjusting is performed prior to affixing the secondcomponent to the heat sink module.

In some embodiments, in accordance with a third optical alignmentrequirement for the first component relative to the second component ofthe diode-pumped solid state laser module, an angle by which the secondcomponent is inserted into the first cavity is adjusted, while the lowerportion of the second component remains in thermal contact with thecooling surface through the deformed thermal conductive medium, wherethe adjusting is performed prior to affixing the second component to theheat sink module.

In some embodiments, the first component of the diode-pumped solid statelaser module includes a laser diode module, where the laser diode moduleincludes an onboard heat sink and a laser chip, wherein the onboard heatsink includes a first side that is affixed to the laser chip and asecond side that is opposite to the first side, and where bonding thefirst component of the diode-pumped solid state laser module to thefirst surface of the heat sink module further includes bonding thesecond side of the onboard heat sink to the first surface of the heatsink module.

In some embodiments, the heat sink module further includes a secondthrough-hole linking the first surface and the second surface, where thecooling surface and the second through-hole form a second cavity with atop opening in the first surface of the heat sink module and a bottomseal in the cooling surface. After bonding the second surface of theheat sink module onto the cooling surface to form the second cavity, thethermal conductive medium is partially filled into the second cavitysuch that the thermal conductive medium is in thermal contact with thecooling surface in the second cavity. A third component of thediode-pumped solid state laser module is inserted into the secondcavity, where the third component includes an upper portion and a lowerportion supporting the upper portion, and where after the insertion, thelower portion of the third component deforms the thermal conductivemedium inside the second cavity and achieves thermal contact with thecooling surface through the deformed thermal conductive medium. Thethird component is affixed to the heat sink module.

In some embodiments, the second component is a laser crystal moduleincluding a lasing crystal and a respective crystal seat supporting thelasing crystal, and the third component is a non-linear crystal and arespective crystal seat supporting the non-linear crystal.

The above process 60 allows adjustment of the optical alignment of thevarious components when placing the components in the through-holes ofthe laser heat sink module(s) in one or more directions, before solidlyaffixing the components to the laser heat sink module(s), therebyreducing the defect rate of the laser assembly.

In some embodiments, a diode-pumped solid state laser module (e.g., thediode-pumped solid state lasers 20 and 30 in FIGS. 1B and 1E) includes aheat sink module, a cooling module, thermal conductive medium, a firstcomponent of the diode-pumped solid state laser module, and a secondcomponent of the diode-pumped solid state laser module. The diode-pumpedsolid state laser module may be assembled using the process 60 shown inFIG. 1F and accompanying descriptions in accordance with someembodiments.

In some embodiments, the heat sink module includes a first surface, asecond surface opposite to the first surface, and at least a firstthrough-hole linking the first surface and the second surface. Thecooling module includes a cooling surface and a thermoelectric coolingsystem (e.g., a thermoelectric cooler (TEC)), and a heat dissipater,where the second surface of the heat sink module is bonded onto thecooling surface of the cooling module, and where the cooling surface ofthe cooling module and the first through-hole in the heat sink moduleform a first cavity with a top opening in the first surface of the heatsink module and a bottom seal in the cooling surface of the coolingmodule. The thermal conductive medium is partially filled within thefirst cavity formed by the cooling surface of the cooling module and thefirst through-hole in the heat sink module. The first component of thediode-pumped solid state laser module is bonded to the first surface ofthe heat sink module such that the first component is in thermal contactwith the first surface of the heat sink module. The second component ofthe diode-pumped solid state laser module is partially inserted into thefirst cavity formed by the cooling surface of the cooling module and thefirst through-hole in the heat sink module, where the second componentincludes a upper portion and a lower portion supporting the upperportion, where the lower portion of the second component deforms thethermal conductive medium inside the first cavity and achieves thermalcontact with the cooling surface through the deformed thermal conductivemedium, and where the second component is affixed to the heat sinkmodule.

In some embodiments, the upper portion and at least a part of the lowerportion of the second component remain outside of the first cavity, andthe lower portion of the second component is affixed to the firstsurface of the heat sink module.

In some embodiments, the second component of the diode-pumped solidstate laser module includes a laser chip and an onboard heat sink thatsupports the laser chip and that is in thermal contact with the laserchip, and where the first component of the diode-pumped solid statelaser module includes a first laser crystal and a first laser crystalseat that supports the first laser crystal and is in thermal contactwith the first laser crystal. This is illustrated by the right portionof the laser 30 in FIG. 1E, for example.

In some embodiments, the first component of the diode-pumped solid statelaser module includes a laser chip and an onboard heat sink thatsupports the laser chip and that is in thermal contact with the laserchip, and where the second component of the diode-pumped solid statelaser module includes a first laser crystal and a first laser crystalseat that supports the first laser crystal and is in thermal contactwith the first laser crystal. This is illustrated in FIG. 1B and by theleft portion of the laser 30 in FIG. 1E, for example.

In some embodiments, the first laser crystal seat includes a topsurface, a bottom surface, and a body between the top surface and bottomsurface of the first laser crystal seat, the first laser crystal seatfurther includes a recess in the top surface of the first laser crystalseat that runs completely through the top surface of the first lasercrystal seat in a first direction, and wherein the first laser crystalis disposed within the recess of the first laser crystal seat and is inthermal contact with two or more inner surfaces of the recess. This isillustrated in FIG. 1D-(3), for example.

In some embodiments, the first cavity is a cylindrical through-hole, andthe first laser crystal seat is a cylindrical body with a linear recessthat runs through the top surface of the cylindrical body. This isillustrated in FIGS. 1C and 1D-(3), for example.

In some embodiments, a vertical position by which the second componentis inserted into the first cavity is adjusted in accordance with a firstoptical alignment requirement for the first component relative to thesecond component of the diode-pumped solid state laser module.

In some embodiments, the lower portion of the second component isaffixed (e.g., by glue dots 41 or other fastening mechanisms, such asscrews or clamps) around the top opening of the first cavity.

In some embodiments, the lower portion of the second component is gluedto the first surface of the heat sink module around the top opening ofthe first cavity in the first surface of the heat sink module.

In some embodiments, a lateral position by which the second component isinserted into the first cavity is adjusted in accordance with a secondoptical alignment requirement for the first component relative to thesecond component of the diode-pumped solid state laser module.

In some embodiments, an angle by which the second component is insertedinto the first cavity is adjusted in accordance with a second opticalalignment requirement for the first component relative to the secondcomponent of the diode-pumped solid state laser module.

In some embodiments, the first component of the diode-pumped solid statelaser module includes a laser diode module, wherein the laser diodemodule includes an onboard heat sink and a laser chip, where the onboardheat sink includes a first side that is affixed to the laser chip and asecond side that is opposite to the first side, and the second side ofthe onboard heat sink is bonded to the first surface of the heat sinkmodule.

In some embodiments, the heat sink module further includes a secondthrough-hole linking the first surface and the second surface, where thecooling surface and the second through-hole form a second cavity with atop opening in the first surface of the heat sink module and a bottomseal in the cooling surface, and where the thermal conductive mediumpartially fills the second cavity such that the thermal conductivemedium is in thermal contact with the cooling surface in the secondcavity, where the diode-pumped solid state laser module further includesa third component, where the third component of the diode-pumped solidstate laser module is partially inserted into the second cavity formedby the cooling surface of the cooling module and the second through-holein the heat sink module, where the third component includes a upperportion and a lower portion supporting the upper portion, where thelower portion of the third component deforms the thermal conductivemedium inside the second cavity and achieves thermal contact with thecooling surface through the deformed thermal conductive medium, andwhere the third component is affixed to the heat sink module.

In some embodiments, the second component is a laser crystal moduleincluding a lasing crystal and a respective crystal seat supporting thelasing crystal, and the third component is a non-linear crystal and arespective crystal seat supporting the non-linear crystal. This isillustrated in FIG. 1B or the left portion of the laser 30 in FIG. 1E,for example.

FIG. 2A shows schematics of an exemplary laser diode (e.g., a laserdiode 1). Typically, a laser diode includes a diode laser chip that ispackaged in TO-CAN packaging. Common TO-CAN packaging includes TO-38,TO-56, TO-9, etc. Sometimes, other types of packaging may be used tomake a laser diode, such as SOT-01, SOT-02, CMT-02, etc. A laser diodewith TO-CAN-56 packaging is shown in FIG. 2A for illustrative purposes.The laser diode 1 shown in FIG. 2A includes a metal support plate 2, ametal enclosure 3, conductive leads 4, an output window 5, and aninsulating layer 6. The diode laser chip is installed on the metalsupport plate 2. The metal support plate 2 is used for dissipating heatgenerated by the diode laser chip. The metal enclosure 3, the outputwindow 5, and the metal support plate 2, together form a sealed space toprotect the diode laser chip. In general, there are several conductiveleads 4 coming out of the backside of the metal support plate 2. Theconductive leads 4 are used to supply electric current to drive thediode laser chip or used for diagnostic purposes. Each of the conductiveleads 4 is insulated from the metal support plate 2 using an insulatinglayer 6.

During operation, a laser beam 7 generated by the diode laser chipleaves the laser diode 1 by passing through the output window 5. Ingeneral, the path of the laser beam 7 is perpendicular to the plane ofthe metal support plate 2. The conductive leads 4 include at least acathode lead and an anode lead, used for supplying electric current todrive the diode laser chip, and an optional ground lead.

As set forth in the Background section, many systems and devices thatuse laser array illumination use laser arrays of semiconductor diodelasers (e.g., such as diode laser 1 in FIG. 2A). When using diode laserarray modules, issues such as optical collimation (e.g., adjustment ofdivergence angles of the diode lasers), heat dissipation, and electricdriving efficiency, etc., need to be addressed. Typically, the heatdissipation/cooling require exposure and contact of heat conductors (orother efficient heat transfer media), while electric driving requiresproper insulation between electric conductors. Since medium used forheat conduction/transfer are typically also good electric conductors andmedium used for electric insulation are typically poor heat conductors,the requirements for cooling and electric driving in diode laser arrayspresent a unique challenge.

To address the above challenge, heat transfer requirements and electricdriving functions of the laser diode module are physically separatedinto different surfaces of the laser array module, such that each can beimplemented without interfering with the other.

In some embodiments, in a single-sided diode laser array, by utilizing aheat sink module with embedded through-holes (stepped or straightthrough-holes), the laser diodes can be placed at least partially withinthe through-holes and the thermal contact area between the laser diodesand the heat sink module can be increased (e.g., due to the increasedcontact area/exposure between the side walls of the through-holes andthe laser diodes), thereby improving the heat dissipation efficiency ofthe heat sink module.

In addition to ensuring sufficient heat dissipation, the driving circuitfor the laser array also needs to be reasonably accommodated.Conventionally, a PCB circuit or a flexible circuit layer is connectedto the laser diodes, and disposed between the laser diode layer and aliquid cooling layer. In general, the size of the driving circuit layeris constrained by the circuit density, and cannot be made very small. Asa result, the driving circuit layer can hinder the heat transfer betweenthe laser diode layer and liquid cooling layer. By utilizing a heat sinkmodule with grooves in the bottom surface to link the through-holes,conductive leads can be placed within the grooves to link the laserdiodes placed within the through-holes in the heat sink module, and theconductive leads can therefore be connected to the driving circuit thatis placed on the side(s) of the heat sink module. This way, the physicalseparation of the driving circuit layer and the heat transfer interfaceis realized, and heat dissipation is no longer hindered by the existenceof the driving circuit layer. The conductive leads can be insulated fromthe rest of the heat sink module, thus the heat sink module does notsignificantly impact the driving efficiency of the electric drivingcircuit. In addition, being good heat conductors in general, theelectrical conductive leads may also facilitate the heat conduction fromthe laser diodes and the heat sink module and/or the liquid coolinglayer. In some embodiments, in order to further reduce the number ofinterfaces and improving heat transfer efficiency, the heat sink modulecan be omitted or integrated with the liquid cooling module, to allowthe laser diodes be in direct thermal contact with the liquid coolingmechanism, and allowing the driving circuit to be disposed on the backside or vertical sides of the liquid cooling module. This configurationalso serves to physically separate the heat conduction layer and thedriving circuit layer. Exemplary embodiments of the single-sided laserdiode array are described below with respect to FIGS. 2B-2Q and 2X-2BE,for example.

In some embodiments, in a double-sided diode laser array module, inorder to maximize the use of the liquid cooling means, the liquidcooling layer is used to cool the laser diodes on both sides of thelaser array module. The diode laser array on each side of the laserarray module is in direct contact with the liquid cooling layer. Theliquid cooling layer is sandwiched between the two laser diode layers ofthe double-sided diode laser array module, while the driving circuitlayers are disposed on the sides of the laser array module. Thisconfiguration allows the physical separation of the heat transferinterface and the driving circuit layer.

The configurations of the laser diode array modules can include laserdiodes of different types and wavelengths. The diode lasers in eacharray may be pointed to different directions in accordance with someembodiments. In some embodiments, the lens used to collimate the laserbeams from the laser diodes may also be placed at least partially withinthe through-holes in the heat sink module, thereby further improving theheat dissipation efficiency. In some embodiments, different types ofcooling mechanisms may be used in the laser array module as needed indifferent application scenarios. In some embodiments, the lenses used tocollimate the laser beams from the laser diode array may be fabricatedas an integrated sheet with lens domes built-in, or as individuallenses. One advantage of using individual lenses is that defectivelenses may be replaced separately without impacting other lenses. Oneadvantage of using an integrated sheet with built-in lens domes is theease of assembly of the laser array module.

FIG. 2B shows the schematics of an exemplary single-sided diode laserarray module 101 with a heat sink module 111 in accordance with someembodiments. FIG. 2B-(1) shows a perspective view of the laser arraymodule 101 from above, and FIG. 2B-(2) shows a perspective view of thelaser array module 101 from below. As shown in FIG. 2B, the laser arraymodule 101 includes a liquid cooling module 102 that cools the laserdiodes during operation. The liquid cooling module 102 includes a liquidcooling tube 103 embedded in a planar substrate layer. During operation,a cooling liquid enters the liquid cooling tube 103 from an inlet 104,and exits the liquid cooling tube 103 from an outlet 105. The coolingliquid can be water or alcohol, in some embodiments. The laser arraymodule 101 further includes a lens array layer (with an array of lenses108 embedded in or resting on a lens array substrate layer 110) abovethe heat sink module 111, and one or more driving circuit layers 118that are disposed perpendicularly relative to the planar heat transferinterface between the heat sink module 111 and the liquid cooling module102.

FIG. 2C is an exploded view of the laser array module 101 showingvarious components of the laser array module 101 and the relativepositions thereof in accordance with some embodiments. As shown in FIG.2C, the laser array module 101 includes a laser diode array 107 thatincludes an array of diode lasers (e.g., an array of diode lasers 1)arranged in a grid pattern (e.g., a rectangular lattice pattern withorthogonal rows and columns). The laser array module 101 furtherincludes a lens array 109 that include an array of lenses 108 atlocations corresponding to the diode lasers 1 in the diode laser array107 (e.g., also in the rectangular lattice pattern over the diodelasers). In some embodiments, the lenses 108 are individual lenses thatare placed within an array of through-holes 119 in a lens arraysubstrate layer 110. In some embodiments, the lenses 108 are integratedwith the lens array substrate layer 110 as a single homogeneous bodymade from a mold, e.g., as an array of lens domes formed on the surfaceof a planar body. In some embodiments, the lenses 108 are disposed abovethe lens array substrate layer 110, e.g., are not disposed within thethrough-holes 119.

As shown in FIG. 2C, the laser array module 101 further includes theheat sink module 111, and the heat sink module 111 includes an array ofthrough-holes (e.g., stepped through-holes 120) at locationscorresponding to the laser diodes 1 in the diode laser array 107. Theback side of the heat sink module 111 includes grooves 121 (e.g., asalso shown in FIG. 2E-(2)).

As shown in FIG. 2C, the laser array module 101 further includes aninsulation array 113, and the insulation array 113 includes an array ofinsulation tubes 112 at locations corresponding to the laser diodes 1(and the locations of the through-holes (e.g., stepped through-holes120)). When the laser array module 101 is assembled, the insulationtubes 112 are inserted within corresponding through-holes (e.g., steppedthrough-holes 120), insulating the conductive leads 4 of the diodelasers 1 from the walls of the through-holes (e.g., the steppedthrough-holes 120) in the heat sink module 111.

As shown in FIG. 2C, the laser array module 101 further includes aninternal array 115 of U-shaped conductive lead connectors 114 and anexternal array 117 of L-shaped conductive lead connectors 116. Theinternal array of U-shaped conductive lead connectors 114 haverespective connectors (aka. legs or arms of the U-shape) that reachwithin the insulator tubes 112 and link the conductive leads 4 of thelaser diodes 1 into a network, and the external array of L-shapedconductive lead connectors 116 have respective connectors (aka. legs orarm of the L-shape) that reach within the insulator tubes 112 and linkthe leads 4 of the outer most layer of laser diodes 1 to the externaldriving circuit layers 118. As shown in FIGS. 2B and 2C, in someembodiments, the driving circuit layers 118 includes driving circuit PCBboards that are affixed to the sides of the heat sink module 111, wherethe sides of the heat sink module 111 (and the driving circuit layers118) are perpendicular to the top and bottom surfaces of the heat sinkmodule 111. As shown in FIG. 2C, the laser array module 101 furtherincludes the liquid cooling module 102 attached to the bottom side ofthe heat sink module 111. The grooves in the bottom side of the heatsink module 111 accommodate the horizontal portions of U-shapedconductive lead connectors 114 and horizontal portions of the L-shapedconductive lead connectors 116, such that the bottom surface of the heatsink module 111 and the top surface of the liquid cooling layer 102 arein close thermal contact with each other for efficient heat exchange.

FIG. 2D shows a schematic of the lens array substrate layer 110 inaccordance with some embodiments. As shown in FIG. 2D, the lens arraysubstrate layer 110 is a substantially planar substrate with an array ofthrough-holes (e.g., stepped through-holes 119) at locationscorresponding to the lenses 108 in the lens array 119 (and the locationscorresponding to the laser diodes 1 in the laser array 107). Eachstepped through-hole 119 includes an upper portion that would fit acorresponding lens 108 (e.g., a cylindrical hole with the same diameterand height as the lens 108). In addition, each stepped through-hole 119includes a lower portion that is slightly smaller than the upperportion, such that a ring-shaped surface or step is created between theupper portion and the lower portion of the stepped through-hole 109. Insome embodiments, the ring-shape surface or step supports the bottomedge of a lens 108, while letting through the laser beam emitted fromthe laser diode below. In some embodiments, the lenses are suspendedabove the ring-shaped surface or step by an optical medium (e.g., atransparent optical gel). In some embodiments, the lenses are affixed tothe top surface of the lens array substrate layer 110 with an air gapbetween each lens and the stepped surface of the stepped through-hole inthe lens array substrate layer 110. In some embodiments, the lenses aredisposed completely outside of the through-holes 109 and affixed to thetop surface of the lens array substrate layer 110 by glue. In someembodiments, the lower portion of the stepped through-hole in the lensarray substrate layer 110 has a diameter slightly larger than the metalenclosure 3 of the laser diode 1, and when the laser array module isassembled, at least the upper portions (e.g., enclosures 3) of the laserdiodes 1 reside within the lower portions of the stepped through-holes119 of the lens array substrate layer 110, e.g., as illustrated in FIG.2H-(2). During operation, the laser beam from each laser diode 1 entersfrom the bottom side of a respective stepped through-hole 119, andpasses through the lens 108 disposed within the respective steppedthrough-hole 119, and the lens 108 adjusts the divergence angle of thelaser beam. In some embodiments, the alignment between the lenses 108and the laser diodes are individually tuned during production to ensurethat the outputs from the plurality of laser diodes are aligned with oneanother once they pass through the respective lenses above the pluralityof laser diodes.

In some embodiments, the lens array substrate layer 110 shown in FIG. 2Dcan be replaced by a lens array substrate layer that includes straightthrough-holes, or through-holes with narrower upper portions and widerlower portions. In some embodiments, the lenses rest on top of the lensarray substrate layer over the through-holes, rather than residing atleast partially within the through-holes. These are illustrated, forexample, in the embodiments shown in Figures AH-AK, AM-AS, AT, AU, andAY.

FIG. 2E shows the schematic of the heat sink module 111 in accordancewith some embodiments. As shown in FIG. 2E-(1), the heat sink module 111includes an array of through-holes (e.g., stepped through-holes 120) ina planar substrate, at locations corresponding to the laser diodes 1 inthe laser array 107. Each stepped through-hole 120 includes an upperportion that is wide enough to fit the upper portion of a respectivelaser diode 1 (e.g., a cylindrical hole with a slightly larger diameterthan that of the support plate 2 of the diode laser 1). In someembodiments, the height of the upper portion of the steppedthrough-holes 120 is smaller than the thickness of the support plates 2for the laser diodes 1, such that at least a portion of the supportplates 2 are protruding above the top surface of the laser diode module111. In addition, each stepped through-hole 120 includes a lower portionthat is slightly smaller than the upper portion, such that a ring-shapedsurface or step is created between the upper portion and the lowerportion of the stepped through-hole 120, and the ring-shape surface orstep supports the bottom edge of the support plate 2 of the laser diode1, while letting the conductive leads 4 of the laser diode 1 pass intothe lower portion of the stepped through-hole 120. The lower portion ofthe stepped through-hole 120 has a height that is sufficient to fit arespective insulator tube 112, such that the insulator tube 112insulates the conductive leads of the laser diode 1 from the innersidewall of the stepped through-hole 120; and with grooves passingthrough the bottoms of a sequence of the stepped through-holes 120(e.g., a row or a column of stepped through-holes 120), the conductivelead connectors 116 and 114 inside these stepped through-holes 120 areinsulated (e.g., physically separated by air gaps) from the inner wallsof the grooves 121 in the bottom surface of the heat sink module 111. Asshown in FIG. 2E-(2), on the bottom side of the heat sink module 111,linear grooves 121 are present to accommodate the horizontal portions ofthe U-shaped conductive lead connectors 114 and the horizontal portionsof the L-shaped conductive lead connectors 116. Each groove 121 passesthrough the lower portions of at least one row or column of steppedthrough-holes 120. The heat sink module 111 is made of good thermalconductors to efficiently transfer heat from the laser diodes 1 to theliquid cooling layer 102 below, while staying electrically insulatedfrom the conductive leads 4 of the laser diodes 1 in the laser diodearray 107.

In some embodiments, the heat sink module 111 shown in FIG. 2E can bereplaced by a heat sink module that includes straight through-holes. Insome embodiments, the support plates of the laser diodes rest on top ofthe heat sink module over the through-holes, rather than residing atleast partially within the through-holes. These are illustrated, forexample, in the embodiments shown in Figures AH, AI, AL-AS, and AT-AX.

FIG. 2F shows schematics of an L-shaped conductive lead connector 116,and a U-shaped conductive lead connector 114 in accordance with someembodiments. As shown in FIG. 2F-(1), the L-shaped conductive leadconnector 116 includes two conductive legs that are at an angle (e.g.,are perpendicular) to each other, and one of the legs includes aconductive boot 124 that encloses a conductive spring-loaded insert 123.The spring-loaded insert 123 includes multiple leaves that will open andpush against the inner wall of the boot 124 when a conductive lead of alaser diode 1 is inserted into the spring-loaded insert 123, such thatthe conductive lead of the laser diode 1 is held firmly in contact withthe conductive boot 124 by the spring-loaded conductive insert 123. TheU-shaped conductive lead connector 114 is similar to the L-shapedconnector 116, except that the U-shaped conductive lead connector 114has two legs/arms 125 that are connected by a linear conductive body122. Each of the two arms/legs 125 of the U-shaped connector 114includes a respective boot 124, and a corresponding spring-loaded insert123 for holding a conductive lead of a laser diode 1.

FIG. 2F-(2) shows the view from below of how the legs/arms 125 of theU-shaped conductive lead connectors 114 and the legs/arms of theL-shaped conductive lead connectors 116 are disposed within theinsulator tubes 112, when assembled in a laser array module. As shown inFIG. 2F-(2), when connecting the leg of a U-shaped conductive leadconnector 114 or a leg of the L-shaped connector 116 with a respectiveconductive lead of a laser diode 1, the leg with the boot 124 and thespring loaded insert 123 thereof are placed within the insulator tube112 from below, and an appropriate lead of the laser diode (not shown inFIG. 2F-(2)) is inserted into the spring-loaded insert from above. TheU-shaped conductive lead connectors 114 are used to connect adjacentlaser diodes in the diode array (e.g., adjacent laser diodes in a row orcolumn of the laser diode array) in series, while the L-shapedconductive lead connectors 116 are used to connect a laser diode (andconsequently other laser diodes that are connected to said laser diodeby the U-shaped connectors 116) to the external driving circuit layer(e.g., a driving PCB board) (e.g., the driving circuit layer 118 placedon the vertical sides of the heat sink module 111). The insulator tube112 is inserted within the lower portion of the stepped through-holes120 (or the lower portion or the entirety of straight through-holes) inthe heat sink module 111 (or variations thereof), and electricallyinsulates the conductive leads 4 of the laser diodes 1 from the heatsink module 111 (or the variations thereof).

FIG. 2G shows the top view and the bottom view of the laser diode array107, in accordance with some embodiments. For example, FIG. 2G-(1) showsthe top view of the laser diode array 107, and FIG. 2G-(2) shows thebottom view of the laser diode array 107, with 3 rows by 5 columns oflaser diodes 1. In the embodiments shown in FIG. 2G, the orientations ofthe laser diodes are substantially identical (e.g., as indicated by therelative positions of the corresponding conductive leads in differentlaser diodes in FIG. 2G-(2)). In some embodiments, small adjustments maybe made to the orientations of the laser diodes 1 to align thepolarization planes of the laser beams from the different laser diodes 1when the laser diodes 1 are place within the through-holes (e.g.,stepped through-holes 120 or straight through-holes 120′). In someembodiments, once the orientations of the laser diodes are adjusted, thelens array substrate layer is placed above the top of the laser diodes1, and fastened to the heat sink module. The lens array substrate layerthus keeps the laser diodes from moving or rotating during operation ofthe laser array module.

In some embodiments, using the laser diode array 107 shown in FIG. 2G,each row of three laser diodes 1 are connected in series by two U-shapedconductive lead connectors 114 and the two laser diodes 1 located at theedges of the array 107 are respectively connected to the externaldriving circuit in the driving circuit layer 118 by two L-shapedconductive lead connectors 116, as shown in FIG. 2H.

FIG. 2H-(1) shows the connections between the laser diodes 1 and theconductive lead connectors 114 and 116 from below. FIG. 2H-(2) shows theside view of the laser array module 101. As shown in FIG. 2H, theconductive leads 4 of the laser diodes 1 are inserted into thespring-loaded inserts 123 in the boots 124 of the conductive leadconnectors 116 and 114 to establish electrical contact between the laserdiodes 1 and the conductive lead connectors 116 and 114. The U-shapedconductive lead connectors 114 and the L-shaped conductive leadconnectors 116 are electrically insulated from the heat sink module 111(or the variations thereof) by the insulator tubes 112. In someembodiments, instead of using insulator tubes 112, other insulatingmaterials may be applied between the conductive lead connectors 114 and116 and the inner walls of the stepped through-holes 120 (or thestraight through-holes 120′), and between the conductive lead connectors114 and 116 and the grooves 121 in the heat sink module 111 (or thevariations thereof), to electrically insulate the heat sink module 111(or the variations thereof) from the electrical leads 4 of the laserdiodes 1 and from the driving circuit layer 118 of the laser arraymodule 101.

As shown in FIG. 2H-(2), the lower portions of the laser diodes 1 areinserted into the lower portion of the stepped through-holes 120 in theheat sink module 111, with the support plates 2 of the laser diodes 1resting on the ring-shaped step surfaces in the stepped through-holes120. The metal enclosures 3 of the laser diodes 1 are at least partiallyinserted into the lower portions of the stepped through-holes 119 in thelens substrate layer 110. The lens array substrate layer 110 and theheat sink module 111 are rested next to each other after alignment basedon the positions of the through-holes 120 and 119. In some embodiments,the lens array substrate layer is adhered to the top surface of the heatsink module 111 with some adhesive medium or other fixation method(e.g., fasteners, screws, etc.). In some embodiments, the thickness ofthe support plates 2 of the laser diodes 1 are greater than the heightof the upper portions of the stepped through-holes 120, such that whenthe lens array substrate layer 110 are laid on top of the heat sinkmodule 111, the bottom surface of the lens array substrate layer 110 issuspended above the top surface of the heat sink module 111 by theprotruding support plates 2 of the laser diodes. When the lens arraysubstrate layer 110 are affixed to the heat sink module 111, e.g., by anadhesive or fasteners, the lens array substrate layer 110 press thesupport plates 2 of the laser diodes against the top surface of the heatsink module 111, so that shift and rotation of the laser diodes areprevented. Each lens 108 is placed within the upper portion of arespective through-hole 119 above a corresponding laser diode 1. Thelens 108 is then affixed to the lens substrate layer 110, e.g., usingglue or other adhesives, at the top edge or the inside walls of thestepped through-holes 119, after the position and orientations of thelenses have been individually adjusted to ensure optical alignment andfocus. For example, when affixing the lenses to the lens substrate layer110, the heights and orientation of the lenses 108 may be adjustedindividually as needed such that the gaps (e.g., an air gap or gapfilled with other high index media) between the lenses 108 and theoutput windows 5 of the laser diodes 1 are of suitable widths to focusthe laser beams from the different laser diodes 1 onto a plane at adesired distance. When a defective lens is discovered during orsubsequent to the assembly of the laser array module 101, the defectivelens may be replaced with another non-defective lens without impactingother lenses in the lens substrate layer 110.

As shown in FIG. 2H-(2), the horizontal portions of the U-shapedconductive lead connectors 114 and the horizontal portions of theL-shaped conductive lead connectors 116 are placed within the grooves121 in the bottom surface of the heat sink module 111 (or the variationsthereof). The bottom surface of the heat sink module 111 (or thevariations thereof) is placed in close thermal contact with the liquidcooling module 102, and transfers heat generated by the laser diodes 1to the liquid cooling module 102 to realize cooling of the laser arraymodule 101. At the same time, the U-shaped conductive lead connectors114 and the L-shaped conductive lead connectors 116 are electricallyseparated and insulated from the heat sink module 111 (or the variationsthereof).

The orientations of the laser diodes 1 shown in FIG. 2G are merelyillustrative. In some embodiments, a different arrangement of the laserdiodes 1 may be used in the laser diode array 107. For example, as shownin FIG. 2I, the orientations of the laser diodes 1 are not all identicalin the laser diode array 107. FIG. 2I-(1) shows the top view of thelaser diode array 107, and FIG. 2I-(2) shows the bottom view of thelaser diode array 107, in accordance with some embodiments. Based on thearrangement of the laser diodes 1 in FIG. 2I, the conductive leads ofthe laser diodes can be connected using the L-shaped conductive leadconnectors 116 and the U-shaped conductive lead connectors 114 inaccordance with the arrangement shown in FIG. 2J, in accordance withsome embodiments. In accordance with the arrangement of the L-shapedconductive lead connectors 116 and the U-shaped conductive leadconnectors 114 shown in FIG. 2J, the grooves 112 can be created inaccordance with the pattern shown in FIG. 2K. The configurations of thelaser diode array 107 and the arrangement of the conductive leadconnectors 114 and 116 can be based on the particular needs of the laserillumination needs and the design of the driving circuit in the drivingcircuit layer. An exemplary laser diode array according to the layoutand orientations shown in FIGS. 2I-2K is also referred to later in thespecification as laser diode array 131. In some embodiments, a laserarray module includes a laser diode array 131 instead of a laser diodearray 101.

As indicated earlier, in some embodiments, the stepped through-holes 119in the lens array substrate layer 110 can be replaced with straightthrough-holes without any steps inside (e.g., straight through-holes119′). In some embodiments, the stepped through-holes 119 in the lensarray substrate layer 110 can be replaced with stepped through-holesthat are wider on top and narrower on the bottom (e.g., steppedthrough-holes 119″). In some embodiments, the stepped through-holes 120in the heat sink module 111 can be replaced with straight through-holeswithout any steps inside (e.g., straight through-holes 120′). In someembodiments, lenses (e.g., lenses 108′) can be placed above the lensarray substrate layer 110 instead of placed within the through-holes 119(or 119′, or 119″) in the lens array substrate layer 110. Depending onthe particular combinations of the types of through-holes in the lensarray substrate layer 110 and the through-holes in the heat sink module111 used in a laser array module, the relative positions of the lenses,the body and support plates of the laser diodes, the through-holes inthe lens array substrate module, and the through-holes in the heat sinkmodule will be adjusted, e.g., as illustrated in FIGS. 2AH-2AS.

As shown in FIG. 2AH, the laser array module 101′ includes a heat sinkmodule 111′ that includes through-holes 120′, where the through-holes120′ are straight through-holes that replace the stepped-through-holes120 shown in FIG. 2C. In FIG. 2AI, the laser array module 101″ includesa heat sink module 111′ with the straight through-holes 120′, andfurther includes a lens array substrate layer 110″, where the lens arraysubstrate layer 110″ includes stepped through-holes 119″ with widerupper portions and narrower lower portions, instead of steppedthrough-holes 119. In addition, the lenses 108′ used in the laser arraymodule 101″ have diameters larger than the diameter of the upperportions of the through-holes 119″, such that the lenses 108′ will notfit within the through-holes 119″ of the lens array substrate layer110″.

In some embodiments, in FIG. 2AI, the laser array module 101′ includes aheat sink module 111′ with the straight through-holes 120′, and furtherincludes a lens array substrate layer 110′, where the lens arraysubstrate layer 110′ includes straight through-holes 119′, instead ofstepped through-holes 119′ or 119″. In addition, the lenses 108′ used inthe laser array module 101′ have diameters larger than the diameter ofthe through-holes 119′, such that the lenses 108′ will not fit withinthe through-holes 119′ of the lens array substrate layer 110′.

FIG. 2AJ illustrates a lens array substrate layer 110′ that includes anarray of straight through-holes 119′. The lens array substrate layer110′ can replace the lens array substrate layer 110 in variousembodiments of the laser array module described herein.

FIG. 2AK illustrates a lens array substrate layer 110″ that includes anarray of stepped through-holes 119″. The stepped through-holes 119″ eachhas a cylindrical upper portion and a cylindrical lower portion that arejoined by a respective ring-shaped surface. The stepped through-holes119″ each have a smaller diameter in the upper portion and a largerdiameter in the lower portion. The lens array substrate layer 110″ canreplace the lens array substrate layer 110 or lens array substrate layer110′ in various embodiments of the laser array module described herein.

FIG. 2AL illustrates a heat sink module 111′ that can replace the heatsink module 111 in various embodiments of the laser array moduledescribed herein. The heat sink module 111′ includes an array ofstraight through-holes 120′ instead of the stepped through-holes 120.

FIGS. 2AM-2AS illustrate some exemplary configurations for the laserarray modules, when various combinations of the heat sink modules (e.g.,111, and 111′) and lens array substrate layers (e.g., 110, 110′ and110″) are used. Descriptions of the example configurations in FIGS.2AM-2AS focus on the key differences from the embodiments shown earlierwith the laser array module 101, descriptions of other components andarrangements thereof in the laser array modules shown in FIGS. 2AM-2AScan be found at least in the descriptions of laser array module 101 andaccompanying FIGS. 2A-2H, for example, and are not repeated here.

As shown in FIG. 2AM, the laser array module 101-a includes a lens arraysubstrate layer 110 (with stepped through-holes 119) and a heat sinkmodule 111 (with stepped through-holes 120), but the lenses 108 arereplaced with larger lenses 108′. The larger lenses 108′ do not residewithin the upper portion of the stepped through-holes 119 of the laserarray substrate layer 110; instead, each lens 108′ is disposed on thetop surface of the lens array substrate layer 110. In this particularconfiguration, the stepped through-holes 119 are each wider in the topportion and narrower in the lower portion. The diameter of the lenses108′ is greater than the diameter of the top portion of the steppedthrough-hole 119. The position of the lenses 108′ can be adjusted duringassembly (before being glued to the surface of the lens array substratelayer 110) such that the alignment and focus requirements of the laserarray module are met by each laser diode-lens pair. One advantage ofhaving a stepped through hole that is wider on top is that the divergingoutput from the laser diodes are less likely to be blocked by the topportion of the through-holes 119. In some embodiments, the through-hole119 needs not have a step along its body, and the diameter of thethrough-hole can be gradually increasing from the bottom to top. In someembodiments, as shown in FIG. 2AM, the metal enclosure of the laserdiode 1 fit within the lower portion of the stepped through-hole 119,and the lower edge of the through-hole 119 rests on top of the edge ofthe support plate of the laser diode 1. This configuration allows thelens support substrate layer to press the laser diodes 1 against thestep within the through-holes 120 in the heat sink module 111, so thatrotation of the laser diodes 1 is prevented.

FIG. 2AN shows another embodiment (e.g., laser array module 101-b) thatis similar to the embodiment shown in FIG. 2AM, except that the lensarray substrate layer 110 with the stepped through-holes 119 arereplaced with the lens array substrate layer 110′ with straightthrough-holes 119′. In this example embodiment, the lenses 108′ areresting on the top surface of the lens array substrate layer 110′ in thesame manner that the lenses 108′ rest on the top surface of the lensarray substrate layer 110 in FIG. 2AM. In this configuration, the metalenclosures of the laser diodes 1 are residing within the lower portionsof the through-holes 119′, such that the lower edges of thethrough-holes 119′ are pressed against the edges of the support platesof the laser diodes 1.

FIG. 2AO shows another embodiment (e.g., laser array module 101-c) thatis similar to the embodiments shown in FIG. 2AM, except that the lensarray substrate layer 110 with the stepped through-holes 119 arereplaced with the lens array substrate layer 110″ with steppedthrough-holes 119″. In this example embodiment, the lenses 108′ areresting on the top surface of the lens array substrate layer 110″ in thesame manner that the lenses 108′ rest on the top surface of the lensarray substrate layer 110 in FIG. 2AM. In some embodiments, as shown inFIG. 2AO, the metal enclosure of the laser diode 1 fit within the lowerportion of the stepped through-hole 119″, and the lower edge of thethrough-hole 119″ rests on top of the edge of the support plate of thelaser diode 1. This configuration allows the lens support substratelayer to press the laser diodes 1 against the step within thethrough-holes 120 in the heat sink module 111, so that rotation of thelaser diodes 1 is prevented. This configuration is suitable in caseswhere the size of the laser diode body is relatively large compared tothe size of the lenses, a narrower top can prevent small lenses fromfalling into the stepped through holes in the lens array substratelayer.

FIG. 2AP illustrates another embodiment (e.g., laser array module 101-d)that is similar to the embodiment shown in FIG. 2H, except that the heatsink module 111 with stepped through-holes 120 are replaced with theheat sink module 111′ with straight through-holes 120′. In this exampleembodiment, the support plates 2 of the laser diodes 1 are supported bythe top surface of the heat sink module 111′ (e.g., on the edges of thethrough-holes 120′), and only the conductive leads of the laser diodes 1are within the through-holes 120′. In addition, the bottom surface ofthe lens array substrate layer 110 rests against the top surfaces of thesupport plates 2 of the laser diodes 1. When the lens array substratelayer 110 is affixed to the heat sink module 111′, the lens arraysubstrate layer 110 presses the support plates 2 of the laser diodes 1against the top surface of the heat sink module 111′, such that rotationand movement of the laser diodes 1 are prevented.

FIG. 2AQ illustrates another embodiment (e.g., laser array module 101-e)that is similar to the embodiment shown in FIG. 2AP, except that thelenses 108′ are placed above the top surface of the lens array substratelayer 110.

FIG. 2AR illustrates another embodiment (e.g., laser array module 101-f)that is similar to the embodiment shown in FIG. 2AQ, except that theheat sink module 111 with stepped through-holes 120 are replaced withthe heat sink module 111′ with straight through-holes 120′. The lenses108′ have greater diameters than the through-holes 120′.

FIG. 2AS illustrates another embodiment (e.g., laser array module 101-g)that is similar to the embodiment shown in FIG. 2AQ, except that thethrough-holes in the lens array substrate layer 110″ have a narrowerupper portion and a wider lower portion. For example, in someembodiments, the size of the output window of the laser diodes arelarge, and through-hole with wider upper portions or straightthrough-holes in the lens array substrate layer will require very largelenses (so that they do not fall through into the holes), and wouldincrease cost. Thus, in such situations, through-holes with narrowerupper portions are desirable.

FIGS. 2H and 2AM-2AS are not an exhaustive listing of all possiblecombinations of the different types of through-holes in the lens arraysubstrate layer and the heat sink module, and the different relativepositions of the laser diodes and lenses. In some embodiments, thelenses 108 are affixed (e.g., by glue) to the top surface of the lenssubstrate layer 110 and suspended above the laser diodes 1 by air gaps.In some embodiments, the diameter of lower portion of the through-holein the lens array substrate layer is smaller than the diameter of themetal enclosure 3 of the laser diode 1. In such embodiments, the bottomsurface of the lens array substrate layer 110 is optionally supported bythe top surfaces of the metal enclosures 3 of the laser diodes 1, andthe lenses are separated from the tops of the metal enclosures 3 by anair gap.

The configurations of the laser array modules (e.g., 101, 101′, 101″,and 101-a to 101-g) shown in FIGS. 2B-2K and 2AH-2AS are merelyillustrative. Variations are possible. For example, FIG. 2L shows alaser array module 136 that is similar to the laser array module 101shown in FIGS. 2B-2K and 2AH-2AS, except that the liquid cooling systemis integrated with the heat sink module, and the driving circuit layeris placed on the sides of the heat sink module with the built-in liquidcooling system. In other words, in the laser array module shown in FIG.2L, a liquid cooling system with built-in grooves and through-holes(e.g., stepped-through-holes) are used to accommodate the laser diodearray, and thus omitting the heat sink module 111 (or variationsthereof) shown in the laser array module 101 (or variations thereof).This configuration reduces the number of thermal interfaces and thusimproves heat transfer efficiency of the laser array module.

FIG. 2L-(1) shows the perspective view of the laser array module 136from above, and FIG. 2L-(2) shows the perspective view of the laserarray module 136 from below, in accordance with some embodiments. FIG.2M shows an exploded view of the laser array module 136 in accordancewith some embodiments.

As shown in FIGS. 2L and 2M, the laser array module 136 includes a heatsink module 137 that is an integration of a heat sink module such as theheat sink module 111 and the liquid cooling system 102 that are shown inFIGS. 2B-2C. As described herein, the heat sink module 137 may also bereferred to as a liquid cooling module 137 since it serves both thefunctions of the heat sink module and the liquid cooling module in thelaser array module 136.

As shown in FIGS. 2L and 2M, the heat sink module/liquid cooling module137 includes an array of through-holes (e.g., stepped through-holes 120)at locations that correspond to the locations of the laser diodes 1 inthe laser diode array 107. On the bottom surface of the heat sink module137, grooves 121 are made to each pass through multiple adjacentthrough-holes (e.g., stepped through-holes 120) in the heat sink module137. In addition, as shown in FIGS. 2L and 2M, the liquid cooling tube103 are embedded in the substrate of the heat sink module 137, e.g., inchannels created in the bottom surface of the heat sink module 137. Asshown in FIGS. 2L and 2M, the laser array module 136 further includesone or more driving circuit layers 138 that are adhered to the verticalside surface(s) of the heat sink module 137. The driving circuit layers138 include openings (e.g., slots) to allow the liquid cooling tubes 103to pass through the driving circuit layers 138 before returning back tothe channels in the heat sink module 137. In some embodiments, theliquid cooling tubes 103 have segments that are parallel to the grooves121 in the bottom surface of the heat sink module 137. In someembodiments, the height of the driving circuit layers 138 is greaterthan the thickness of the heat sink module 137 and the driving circuitlayers 138 may also extend to cover the sides of the lens array moduleas well, e.g., covering the sides of the lens substrate layer 110 (orvariations thereof) as shown in FIGS. 2L and 2M.

As shown in FIGS. 2L and 2M, the laser array module 136 also includes alens array (e.g., lens array 109) that includes lenses (e.g., lenses108) arranged in an array pattern. The laser array module 136 furtherincludes a lens array substrate layer (e.g., lens array substrate layer110) that includes an array of through-holes (e.g., steppedthrough-holes 119) at locations corresponding to the laser diodes 1 inthe laser diode array 107. The laser array module 136 further includesan array 113 of insulator tubes 112, an array 115 of U-shaped conductivelead connectors 114, and an array 117 of L-shaped conductive leadconnectors 116. When assembled, the lenses (e.g., lenses 108) are placedwithin (or above) the lens array substrate layer (e.g., the lens arraysubstrate layer 110, 110′, or 110″) and the laser diodes 1 are placed atleast partially within the through-holes (e.g., stepped through-holes120) in the heat sink module 137 in a manner as shown in FIG. 2H-(2) (orvariations thereof as described in Figures AM-AS). Furthermore, theinsulator tubes 112 are placed within the through-holes (e.g., steppedthrough-holes 120) and the laser diodes 1 are connected to the U-shapedconductive lead connectors 114 and the L-shaped conductive leadconnectors 116 in the manner shown in FIG. 2H as well (or variationsthereof as described in Figures AM-AS). The L-shaped conductive leadconnectors 116 connect the leads 4 of the laser diodes 1 with thedriving circuit layers 138.

Although the example shown in FIGS. 2L and 2M is a modification based ona configuration of the laser array module 101 shown in FIG. 2B, similarmodifications can be applied to laser array modules 101′, 101″, 101-athrough 101-g shown in FIGS. 2AM-2AS as well. For example, FIGS. 2AT and2AU illustrate example laser array modules 136′ and 136″.

In FIG. 2AT, the laser array module 136′ includes a heat sink module137′ which is an integrated heat sink and liquid cooling module. Theheat sink module 137′ includes straight through-holes 120′ that replacethe stepped through-holes 120. The relative positions of the laser arraydiodes 1, the insulator tubes 112, the through-holes 120′ in the heatsink module 137′, the lens array substrate layer 110, and the lenses 108are similar to those shown in FIG. 2AP, for example. The relativepositions of the driving circuit module 138, liquid cooling tubes 103,conductive lead arrays 115 and 117, insulator tubes 112, and the heatsink module 137′ are similar to those shown in FIG. 2M, for example.

Similarly, in FIG. 2AU, laser array module 136″ includes an integratedheat sink module 137′ with straight through-holes 120′. The laser arraymodule 136″ is similar to the laser array module 136′ shown in FIG. 2AT,except that the lens array substrate layer 110″ include steppedthrough-holes 119″ that are narrower in the lower portions and wider inthe upper portions. The relative positions of the laser array diodes 1,the insulator tubes 112, the through-holes 120′ in the heat sink module137′, the lens array substrate layer 110″, the through-holes 119″, andthe lenses 108′ are similar to those shown in FIG. 2AS, for example. Therelative positions of the driving circuit module 138, liquid coolingtubes 103, conductive lead arrays 115 and 117, insulator tubes 112, andthe heat sink module 137′ are similar to those shown in FIG. 2M, forexample.

Other variations of the heat sink module 137 can be based on theconfigurations (e.g., with various combinations of the through-holes 120and 120′ in the heat sink module, the through-holes 119, 119′, 119″ inthe lens array substrate layer, and lenses 108 and 108′ in the lensarray) shown in FIGS. 2AM-2AO and 2AQ-2AR, for example. FIGS. 2L-2M, 2ATand 2AU show that the liquid cooling tube 103 is placed within channelscreated in the bottom surface of the heat sink module 137, 137′ and/or137″ in accordance with some embodiments. FIG. 2N shows the heat sinkmodule 137 with the liquid cooling tube 103 placed within channelscarved in the bottom surface of the heat sink module 137. FIG. 2N-(2)also shows that the liquid cooling tube 103 includes a plurality oflinear segments that run parallel to the grooves 121 in the bottomsurface of the heat sink module 137. It is also possible to createchannels in the top surface of the heat sink module to accommodate theliquid cooling tube 103 in accordance with some embodiments. Forexample, in the heat sink module 139 shown in FIG. 2O, the liquidcooling tube 103 is placed within channels carved in the top surface ofthe heat sink module 139.

In some embodiments, when the laser diodes 1 in the diode array 107 areoriented such that only parallel grooves 121 need to be created in thebottom surface of the heat sink module (e.g., as shown in FIG. 2G), thechannels for the liquid cooling tube 103 may be created on either thetop surface or the bottom surface of the heat sink module (e.g., asshown in FIGS. 2N and 2O, respectively). However, in some embodiments,when the laser diodes 1 in the diode array 107 are oriented such thatcrossing of the grooves 121 in the bottom surface of the heat sinkmodule are required (e.g., as shown in FIGS. 2I-2K), the channels forthe liquid cooling tube 103 may be created in the top surface of theheat sink module to avoid interfering with the positioning of thegrooves 121 in the bottom surface of the heat sink module. For example,as shown in FIG. 2P, the channels for the liquid cooling tube 103 arecreated in the top surface of the heat sink module 147, while thegrooves 121 for the U-shaped conductive lead connectors and the L-shapedconductive lead connectors are created in the bottom surface of the heatsink module 147. In some embodiments, crossing of the grooves 121 maycoexist with the channels for liquid cooling tube 103 on the same sideof the heat sink module, provided that the depths of the grooves andchannels are such that the conductive leads and the cooling tube 103will not interfere with each other at the same depth level (e.g., thechannels are deeper than the grooves, or vice versa).

The examples shown in FIGS. 2N-2P are based on heat sink modules thathave stepped through-holes 120. Similar configurations of the heat sinkmodule, the grooves, and the liquid cooling tubes, can also be based onthe heat sink modules that have straight through-holes 120′. Forexample, FIG. 2AV shows the top and bottom views of an integrated heatsink module 137′ with straight through-holes 120′. Similar to the heatsink module 137 shown in FIG. 2N, the heat sink module 137′ includes thechannels on the bottom surface of the heat sink module 137′, and thechannels include segments that are parallel to the linear grooves 121 inthe bottom surface of the heat sink module 137′.

In another example, FIG. 2AW shows the top and bottom views of anintegrated heat sink module 139′ with straight through-holes 120′.Similar to the heat sink module 139 shown in FIG. 2O, the heat sinkmodule 139′ includes the channels on the top surface of the heat sinkmodule 139′, and the channels include segments that are parallel to thelinear grooves 121 in the bottom surface of the heat sink module 139′.

In another example, FIG. 2AX shows the top and bottom views of anintegrated heat sink module 147′ with straight through-holes 120′.Similar to the heat sink module 147 shown in FIG. 2P, the heat sinkmodule 147′ includes the channels on the top surface of the heat sinkmodule 147′, and the channels include segments that are parallel to someof the linear grooves 121 in the bottom surface of the heat sink module147′, but perpendicular to some other linear grooves 121 in the bottomsurface of the heat sink module 147′.

In some embodiments, the layer of substrate with the grooves 121 can befabricated separately from the layer of substrate with the channels foraccommodating the liquid cooling tube 103. The layer of substrate withthe channels for accommodating the liquid cooling tube 103 also includethe upper portions of the stepped through-holes 120, and optionally partof the lower portion of the stepped through-holes 120. The layer ofsubstrate with the grooves also includes at least part of the lowerportions of the stepped through-holes 120. The heat sink module iscreated by aligning the respective portions of the stepped through holes120 in both layers of substrate and adhere the two layers together. FIG.2Q illustrates an example heat sink module 149 having the two-layerconfiguration. The circuit driving layer 138 are placed on the sides ofthe heat sink module 149 that are not passed through by the liquidcooling tube 103.

In some embodiments, when the liquid cooling system is integrated withthe heat sink module, it is also possible to include the driving circuitlayer next to the bottom surface of the heat sink module, or have aportion of the driving circuit layer wrap down onto the bottom surfaceof the heat sink module from the vertical side(s) of the heat sinkmodule, in accordance with some embodiments. The heat exchange interfaceis still separated from the driving circuit layer in suchconfigurations, provided that the conductive lead connectors 114 and 116are completely held within the grooves 121, and are physically separatedfrom the driving circuit layer or portions thereof that are placedadjacent to the bottom surface of the heat sink module.

FIGS. 2B-2Q and 2AH-2AX illustrate the configurations of single-sidedlaser array modules in accordance with some embodiments. In someembodiments, many of the features of the single-sided laser array modulemay be adapted for use in a double-sided laser array module. Forexample, in some embodiments, two diode laser arrays may share the sameliquid cooling system sandwiched in between the two diode laser arrays.

FIG. 2R illustrates a double-sided laser array module 157 that has asingle liquid cooling layer shared by two diode arrays. FIG. 2R-(1)shows a perspective view of the double-sided laser array module 157 fromabove, where the upper portion of the laser array module 157 is liftedaway from the lower portion of the laser array module 157 to reveal theinternal features of the double-sided laser array module 157. FIG.2R-(2) shows a perspective view of the double-sided laser array module157 with the upper and lower portions fitted together.

As shown in FIG. 2R, the structure of the upper portion of thedouble-sided laser array module 157 is the same as the single-sidedlaser array module 101 (or a variation thereof) or the single-sidedlaser array module 136 (or a variation thereof). The upper portion ofthe double-sided laser array module 157 has its own driving circuitlayers 118 on the sides of the laser array module above the liquidcooling layer 102/137. In some embodiments, the driving circuit layersof the upper portion of the double-sided laser array module 157 may alsocover the sides of the liquid cooling layer 102/137, with slots to allowthe liquid cooling tubes 103 to pass through (e.g., as does the drivingcircuit layer 138 shown in FIGS. 2M, 2AT, and 2AU).

As shown in FIG. 2R, the channels for accommodating the liquid coolingtube 103 are created in the bottom surface of the liquid cooling layer102/137. As shown in FIG. 2R, the lower portion of the double-sidedlaser array module 157 is the same as the single-sided laser arraymodule 101 (or a variation thereof) or the single-sided laser arraymodule 136 (or a variation thereof), without the liquid cooling layer102/137. The lower portion of the double-sided laser array module 157shares the liquid cooling layer 102/137 with the upper portion of thedouble-sided laser array module 157. The lower portion of thedouble-sided laser array module 157 has its own set of lens arrays, heatsink module, driving circuit layers, and conductive lead connectors. Inthe example shown in FIG. 2R, the liquid cooling layer and the heat sinkmodules of the top and bottom laser diode arrays are separate layers,and the liquid cooling layer accepts the heat transferred from the heatsink modules of both the top and the bottom laser diode arrays. Withrespect to the bottom laser diode array, the channels are carved in thetop surface of the liquid cooling module (the surface that is next tothe bottom surface of the heat sink module).

Similar double-sided laser array modules can be built based on laserarray modules (e.g., laser array modules 101′, 101″, 101-a to 101-g) andsubcomponents thereof (e.g., heat sink modules 111, 111′, 136, 136′,137, 137′, 139, 139′, 147, 147′, and 149, and lens array substratelayers 110, 110′, and 110″, etc.), as shown in FIGS. 2AH-2AX.

In some embodiments, in addition to sharing the liquid cooling layer, adouble-sided laser diode array module can further share the heat sinkmodule and/or the driving circuit layers. As shown in FIGS. 2S and 2T, adouble-sided laser array module 162 includes an integrated heatsink/liquid cooling module 161, where the integrated heat sink/liquidcooling module 161 serves the laser arrays 131 (e.g., laser arrays 131-1and 131-2) on both sides of the double-sided laser array module 162 (andanalogously, suffixes “x-1” and “x-2” are used to refer to a subset ofcomponents x in the double-sided laser array module that are associatedwith the laser array 131-1, and 131-2, respectively).

In some embodiments, the integrated heat sink/liquid cooling module 161includes two arrays of through-holes (e.g., two arrays of steppedthrough-holes 120 (e.g., an array of stepped through-holes 120-1 and anarray of stepped through-holes 120-2)), each array of through-holes(e.g., stepped through-holes 120) accommodate a respective laser diodearray 131 facing a respective side (e.g., the top-side or the bottomside, as described herein, the laser-diode array 131-1 face the top sideof the laser diode array 162, and the laser diode array 131-2 face thebottom side of the laser diode array 162) of the double-sided laserarray module 161. Furthermore, the two arrays of through-holes (e.g.,stepped through-holes 120) are offset from each other by a respectivedistance (e.g., a half the grid size of the array of through-holes(e.g., stepped through-holes 120)).

FIG. 2S-(1) shows the perspective view of the integrated heatsink/liquid cooling module 161 from above, and FIG. 2S-(2) shows theperspective view of the integrated heat sink/liquid cooling module 161from below, in accordance with some embodiments. As shown in FIG. 2S-(1)and FIG. 2T, the array of through holes (e.g., stepped through-holes120-1, or straight through-holes) are for accommodating the laser diodearray 131-1 facing the top side of the double-sided laser array module162. As shown in FIG. 2S-(2) and FIG. 2T, the array of through-holes(e.g., stepped through-holes 120-2 or straight through-holes) are foraccommodating the laser diode array 131-2 facing the bottom side of thedouble-sided laser array module 162.

As shown in FIG. 2S-(1), grooves 121-2 are formed in the top surface ofthe heat sink module 161, and each groove 121-2 links the lower portionsof a sequence of stepped through-holes 120-2. As shown in FIG. 2S-(2),grooves 121-1 are formed in the bottom surface of the heat sink module161, and each groove 121-1 links the lower portions of a sequence ofthrough-holes (e.g., stepped through-holes 120-1).

As shown in FIGS. 2S-(1) and 2S-(2), the liquid cooling tube 103includes multiple linear portions that are connected by curved portions,and the linear portions run parallel to one subset of linear grooves(e.g., the linear grooves 121-1, or the linear grooves 121-2) and runperpendicular to the other subset of linear grooves in the same gridpattern.

As shown in FIGS. 2S-(1) and 2S-(2), the liquid cooling tube 103 residesin channels that are opened from the bottom surface of the heat sinkmodule 161, in accordance with some embodiments. In some embodiments,the channels for the liquid cooling tube 103 are opened from the topsurface of the heat sink module 161. In some embodiments, the channelsfor the liquid cooling module are completely embedded between the topand bottom surfaces of the heat sink module. In some embodiments, theliquid cooling tube 103 is replaced with a fluid channel created withinthe top and bottom surfaces of the heat sink module, with the beginningof the fluid channel connected to the inlet 104, and the end of thefluid channel connected to the outlet 105, e.g., as shown in FIGS. 2AAand 2AE, and FIGS. 2BA and 2BC.

FIG. 2T shows an exploded view of the double-sided laser array module162. As shown in FIG. 2T, the components of the double-sided laser arraymodule 162 are substantially identical on both sides of the heat sinkmodule 161.

As shown in FIG. 2T, on the top side of the laser array module 162, afirst lens array 109-1 with an array of lenses 108-1 are placed withinan array of first through-holes (e.g., first stepped through-holes119-1) in a first lens array substrate 110-1 (e.g., the lens arraysubstrate 110 in FIG. 2D). The first through-holes (e.g., the firststepped through holes 119-1) in the first lens array substrate 110-1also accommodate the upper portions of the laser diodes 1-1 in the firstlaser diode array 131-1, e.g., in the manner shown in FIG. 2H-(2). Thelaser diodes 1-1 in the first laser diode array 131-1 are inserted inthe array of through-holes (e.g., stepped through-holes 120-1) in theheat sink module 161. The lower portions of the laser diodes 1-1 in thefirst laser diode array 131-1 are separated (and electrically insulated)from the walls of the through-holes (e.g., stepped through-holes 120-1)by a first array 113-1 of respective insulator tubes 112-1. On thebottom surface of the heat sink module 161, grooves 121-1 are created tolink respective sequences of through-holes (e.g., stepped through-holes120-1). In addition, in some embodiments, channels are opened from thebottom surface of the heat sink module 161 to accommodate a liquidcooling tube 103. Lastly, the array 115-1 of U-shaped conductive leadconnectors 114-1 link the conductive leads of the laser diodes 1-1 inrespective rows (or columns) in the first laser diode array 131-1, andthe array 117-1 of L-shaped conductive lead connectors 116-1 link theconductive leads of the laser diodes 1-1 on the edges of the array 131-1to the driving circuit layer(s) (not shown in FIG. 2T) that are disposedon the vertical side(s) of the laser array module 162 (e.g., at leastpartially covering the vertical sides of the heat sink module 161).

As shown in FIG. 2T, on the reverse side of the laser array module 161,a second lens array 109-2 with an array of lenses 108-2 are placedwithin a second array of through-holes (e.g., a second array of steppedthrough-holes 119-2) in a second lens array substrate 110-2 (e.g., thelens array substrate 110 in FIG. 2D). The through-holes (e.g., steppedthrough holes 119-2) in the second lens array substrate 110-2accommodate the upper portions of the laser diodes 1-2 in the secondlaser diode array 131-2, e.g., in the manner shown in FIG. 2H-(2). Thelaser diodes 1-2 in the second laser diode array 131-2 are inserted inthe array of through-holes (e.g., stepped through-holes 120-2 (notclearly visible in the view shown in FIG. 2T)) in the heat sink module161. The lower portions of the laser diodes 1-2 (e.g., including theconductive leads of the laser diodes 1-2) in the second laser diodearray 131-2 are separated (and electrically insulated) from the walls ofthe stepped through-holes 120-2 by a second array 113-2 of respectiveinsulator tubes 121-2. On the top surface of the heat sink module 161,grooves 121-2 are created to link respective sequences of through-holes(e.g., stepped through-holes 120-2).

As shown in FIG. 2T, the arrays of through-holes in the lens supportmodule (e.g., stepped through-holes 119-1 and 119-2), the arrays ofthrough-holes in the heat sink module (e.g., stepped through-holes 120-1and 120-2), and corresponding laser diode arrays 131-1 and 131-2 areoffset from each other, respectively, so that each row of laser diodes1-1 from the first laser diode array 131-(1) are offset from acorresponding row of laser diodes 1-2 from the second laser diode array131-(2), and each column of laser diodes 1-1 from the first laser diodearray 131-(1) are offset from a corresponding column of laser diodes 1-2from the second laser diode array 131-(2).

FIG. 2U illustrates the relative positions of the lenses 108, the laserdiodes 1, the insulator tubes 112, the conductive lead connectors 114and 116, the through-holes in the lens support module (e.g., the steppedthrough-holes 119), the through-holes in the heat sink module (e.g., thestepped through-holes 120), and the grooves 121, in the double-sidedlaser array module 162. FIG. 2U-(1) shows the double-sided laser arraymodule 162 from a first vertical cross-section through a row or a columnof laser diodes 1-1 facing the top side of the double-sided laser arraymodule 162. FIG. 2U-(2) shows the double-sided laser array module 162from a second vertical cross-section through a row or a column of laserdiodes 1-2 facing the bottom side of the double-sided laser array module162. FIG. 2U is similar to FIG. 2H-(2) in the relative positions of thecomponents serving each side of double-sided laser array module 162.Similar double-sided laser array modules can also be built according tothe configurations shown in FIGS. 2AM-2AS, for example.

FIG. 2V illustrates an exploded view of another double-sided laser arraymodule 169 in accordance with some embodiments. The double-sided laserarray module 169 are substantially similar to the double-sided laserarray module 162 when assembled, except that the grooves for connectingthe conductive leads of the laser diodes 1 are moved to the surfaces ofthe lens array substrate layer, instead of the top and bottom surfacesof the heat sink module. Correspondingly, through-holes foraccommodating the lower portions of the laser diodes 1 in a respectivelaser diode array 131 are created in each lens array substrate layer, inaddition to the through-holes for accommodating a respective array oflenses.

As shown in FIG. 2V, the heat sink module 166 of the double-sided laserarray module 169 includes a first array of through-holes (e.g., steppedthrough-holes 120-1 or straight through-holes) to accommodate a firstarray 131-1 of laser diodes 1-1 (facing the bottom side of thedouble-sided laser array module 169 in FIG. 2V), and a second array ofthrough-holes (e.g., stepped through-holes 120-2 or straightthrough-holes) to accommodate a second array 131-2 of laser diodes 1-2(facing the top side of the double-sided laser array module 169 in FIG.2V). The two arrays of through-holes (e.g., stepped through-holes 120-1and 120-2, or corresponding straight through-holes) are offset from eachother by a respective distance (e.g., by half of the grid distance) ineach of the row direction and the column direction. As shown in FIG. 2V,the channels for the liquid cooling tube 103 are created in the topsurface of the heat sink module 166.

As shown in FIG. 2V, the lens array substrate layer 167 is used toaccommodate a first array 109-2 of lenses 108-2 (which corresponds tothe second array of lenses 108-2 in FIG. 2T) residing on the top side ofthe double-sided laser array module 169. On the reverse side of thedouble-sided laser array module 169, the lens array substrate layer 168is used to accommodate a second array 109-1 of lenses 108-1 (whichcorresponds to the first array of lenses 108-1 in FIG. 2T) residing onthe bottom side of the double-sided laser array module 169. In addition,through-holes 171-1 are created in the lens array substrate layer 167 atlocations corresponding to the laser diodes 1-1 in the first laser diodearray 131-1, to accommodate the lower portions (e.g., conductive leads)of the laser diodes 1-1 in the first laser diode array 131-1. Grooves173-1 are created in the top surface of the lens array substrate layer167, where each groove 173-1 links a respective row or column ofthrough-holes 171-1. Similarly, through-holes 171-2 are created in thelens array substrate layer 168 at locations corresponding to the laserdiodes 1-2 in the first laser diode array 131-2, to accommodate thelower portions (e.g., conductive leads) of the laser diodes 1-2 in thefirst laser diode array 131-2. Grooves 173-2 are created in the bottomsurface of the lens array substrate layer 168, where each groove 173-2links a respective row or column of through-holes 171-2.

As shown in FIG. 2V, when assembling the double-sided laser array module169, an array 113-1 of insulator tubes 112-1 are inserted from the topside of the lens array substrate layer 167 into the through holes 171-1,and optionally further into the stepped through-holes 120-1 in the heatsink module 166; the laser diodes 1-1 in the first laser diode array131-1 are inserted into the stepped through holes 120-1 from the bottomside of the heat sink module 166, and the conductive leads of the laserdiodes 1-1 pass into the through-holes 171-1 in the lens array substratelayer 167, and are insulated from the walls of the through-holes 171-1and 120-1 by the insulator tubes 112-1. Conductive lead connectors 114-1are used to connect the conductive leads of the laser diodes 1-1 betweenadjacent through-holes 171-1, and conductive lead connectors 116-1 areused to connect the conductive leads of the laser diodes 1-1 on theedges of the laser diode array 113-1 to the driving circuit layers (notshown) residing on the vertical sides of the double-sided laser arraymodule 169. The horizontal portions of the conductive lead connectors114-1 and 116-1 in the arrays 115-1 and 117-1 reside within the grooves173-1 in the top surface of the lens array substrate layer 167.

As shown in FIG. 2V, on the reverse side, when assembling thedouble-sided laser array module 169, an array 113-2 of insulator tubes112-2 are inserted from the bottom side of the lens array substratelayer 168 into the through holes 171-2, and optionally further into thestepped through-holes 120-2 in the heat sink module 166; the laserdiodes 1-2 in the second laser diode array 131-2 are inserted into thestepped through holes 120-2 from the top side of the heat sink module166, and the conductive leads of the laser diodes 1-2 pass into thethrough-holes 171-2 in the lens array substrate layer 168, and areinsulated from the walls of the through-holes 171-2 and 120-2 by theinsulator tubes 112-2. Conductive lead connectors 114-2 are used toconnect the conductive leads of the laser diodes 1-2 between adjacentthrough-holes 171-2, and conductive lead connectors 116-2 are used toconnect the conductive leads of the laser diodes 1-2 on the edges of thelaser diode array 113-2 to the driving circuit layers (not shown)residing on the vertical sides of the double-sided laser array module169. The horizontal portions of the conductive lead connectors 114-2 and116-2 in the arrays 115-2 and 117-2 reside within the grooves 173-2 inthe bottom surface of the lens array substrate layer 168.

The lenses 108-1 in the lens array 109-1 for the first laser diode array131-1 are inserted into the through-holes 110-1 from the bottom side ofthe lens array substrate layer 168, while the lenses 108-2 in the lensarray 109-2 for the second laser diode array 131-2 are inserted into thethrough-holes 110-2 from the top side of the lens array substrate layer167.

FIG. 2W illustrate the cross-sectional view of the double-sided laserarray module 169. FIG. 2W-(1) illustrates a cross-section through a rowor column of laser diodes 108-1 in the first laser diode array 131-1.FIG. 2W-(2) illustrates a cross-section through a row or column of laserdiodes 108-2 in the second laser diode array 131-2. As shown in FIG. 2W,the structure of the double-sided laser array module 169 is similar tothe structure of the double-sided laser array module 162 shown in FIG.2U, except that the grooves for accommodating the horizontal portions ofthe conductive lead connectors 114 and 116 are moved further away fromthe upper portions of the laser diodes 1 (e.g., for the laser diodearray facing the top side of the double-sided laser array module, thegrooves are moved from the bottom surface of the heat sink module to thebottom surface of the lens array substrate layer at the bottom side ofthe double-sided laser array module). In addition, the through-holes foraccommodating the conductive leads of the laser diodes are extended fromthe heat sink module to the lens array substrate layer (e.g., for thelaser diode array facing the top side of the double-sided laser arraymodule, the through-holes for accommodating the laser diodes extend fromthe top surface of the heat sink module through the lens array substratelayer at the bottom side of the double-sided laser array module).

In the double-sided laser array module 169 shown in FIGS. 2V and 2W, theheat sink module 166 may be integrated with the lens array substratelayers 167 and 168, and the integrated heat sink module serves tosupport the lenses on both sides of the double-sided laser array module,and to serve as the heat sink module and liquid cooling module of thedouble-sided laser array module. Although the driving circuit layers arenot shown in FIGS. 2T-2W, a person skilled in the art can appreciatethat the driving circuit layers can be attached to one or more of thevertical sides of the double-sided laser array module, and may extendbeyond the layers/modules that accommodate the horizontal portions ofthe conductive lead connectors 114 and 116.

Similar double-sided laser array modules as those shown in FIGS. 2S-2Wcan be built based on the configurations shown with respect to laserarray modules 101′, 101″, 101-a to 101-g and subcomponents thereof(e.g., heat sink modules 111, 111′, 136, 136′, 137, 137′, 139, 139′,147, 147′, and 149, and lens array substrate layers 110, 110′, and 110″,etc.), as shown in FIGS. 2AH-2AX.

As disclosed herein, a lens array module includes an array of lenses anda lens array substrate layer that accommodate the lenses (andoptionally, accommodate other structural features and components (e.g.,grooves, conductive lead connectors, conductive leads of laser diodes,housing of laser diodes, etc.) of the laser array module). FIG. 2Xillustrates the formation of a lens array module in accordance with someembodiments. In FIG. 2X, the lens array module 174 is formed with twoseparate substrate layers 176 and 178. As shown in FIG. 2X-(1), thesubstrate layers 176 and 178 each include a respective array of straightthrough-holes. The diameters of through-holes 177 in the substrate layer176 are slightly larger than the diameters of the lenses 108, such thatthe lenses 108 can snuggly fit within the through-holes 177. Thethrough-holes 179 in the substrate layer 178 have slightly smallerdiameters than the through-holes 177 in the substrate layer 176. Thelocations of the through-holes 177 and 178 in the two substrate layerscorrespond to the locations of the laser diodes 1 in the laser arraymodule.

FIG. 2X-(2) shows that when the two substrate layers 176 and 178 areplaced adjacent to each other, an array of stepped through-holes isformed. The lenses 108 are placed within the stepped through-holes, andsupported by the edges of the straight through-holes 179 in the lowersubstrate layer 178. In some embodiments, the thickness of the lowersubstrate layer 178 is selected based on the size of gap needed betweenthe lenses and the laser diodes.

In FIG. 2AY, the lens array module 174′ is formed with single substratelayer 178 with an array of straight through-holes 179. The diameters ofthrough-holes 179 in the substrate layer 174′ are slightly smaller thanthe diameters of the lenses 108, such that the lenses 108 can sit abovethe through-holes 179 without falling through. The locations of thethrough-holes 179 correspond to the locations of the laser diodes 1 inthe laser array module.

FIG. 2Y shows an exemplary lens array module 175 with integrated lensdomes on a substrate layer. The lens array module 175 optionallyaccommodates other structural features and components (e.g., grooves,conductive lead connectors, conductive leads of laser diodes, housing oflaser diodes, etc.) of the laser array module in some embodiments. Asshown in FIG. 2Y-(1), the lens array module 175 includes a substantiallyplanar substrate portion 181, with an array of lens domes 180 protrudingfrom the planar portion. In some embodiments, the integrated lens arraymodule is formed using a mold from a high index optical material, e.g.,glass, or other high-index plastics, polymers, etc.

FIG. 2Z illustrates another heat sink module 183 that may be used in thelaser array modules disclosed herein, in accordance with someembodiments. The heat sink module 183 is integrated with a liquidcooling layer, and includes a liquid cooling channel with an inlet 104and an outlet 105. In some embodiments, the liquid cooling channel is afluid channel or a series of interconnected fluid chambers createdwithin the body of the heat sink module, and is not necessarily in theform of a circular tube embedded in the body of the heat sink module.The heat sink module 183 may replace the heat sink module 137 or 139 inthe laser array module in some embodiments.

FIG. 2Z-(1) shows a perspective view of the heat sink module 183 fromabove, and FIG. 2Z-(2) shows a perspective view of the heat sink module183 from below. As shown in FIG. 2Z, the heat sink module 183 includes afirst portion 184 and a second portion 185 that are adhered together toform an enclosure in which a cooling liquid may circulate to cool theheat sink module 183. The inlet 104 and outlet 105 for the coolingliquid are opened in the body (side walls) of the first portion 184, toallow a cooling liquid to enter and exit the enclosure (fluid channel)created by the first portion 184 and the second portion 185 of the heatsink module 183.

As shown in FIG. 2Z-(1), an array of through-holes (e.g., steppedthrough-holes (to serve as the upper portions of stepped through-holes120) are opened in the first portion 184 of the heat sink module 183 toaccommodate the upper portions of an array of the laser diodes 1. Asshown in FIG. 2Z-(2), an array of through-holes (to serve as the lowerportions of stepped through-holes 120) are opened to accommodate thelower portions of the array of laser diodes 1. Each through-hole in thefirst portion 184 corresponds to a respective through-hole in the secondportion 185, and the two through-holes have the same lateral position intheir respective portions. In addition, as shown in FIG. 2Z-(2), lineargrooves 121 are created in the surface of the second portion 185 to eachlink a respective row or column of through-holes in the second portion.

In some embodiments (not shown in FIG. 2Z-(1)), an array of straightthrough-holes are opened at corresponding positions in each of the firstportion 184 of the heat sink module 183 and the second portion 185 toaccommodate the lower portions of an array of the laser diodes 1. Inaddition, as shown in FIG. 2Z-(2), linear grooves 121 are created in thesurface of the second portion 185 to each link a respective row orcolumn of through-holes in the second portion.

FIG. 2AA shows more details of the first portion 184 of the heat sinkmodule 183, in accordance with some embodiments. FIG. 2AA-(1) shows aperspective view of the first portion 184 from a first side, and FIG.2AA-(2) shows a perspective view of the first portion 184 from a secondside. As shown in FIG. 2AA-(1), the inside of the first portion 184 arehollowed out leaving only solid materials around locations of thestepped through holes (serving as stepped through-holes 120). Forexample, in some embodiments, the inside of the first portion ishollowed out, leaving a shell, and a plurality of islands andprotrusions of solid materials attached to the shell. On each of theislands or protrusions, there are one or more stepped through-holes(e.g., a row or column of stepped through-holes from the array ofstepped through-holes serving as stepped through-holes 120). Inaddition, an inlet 104 and an outlet 105 are created in the side wallsof the shell, allowing a cooling fluid to enter into and exit thehollowed interior region within the first portion 184.

FIG. 2AB shows the second portion 185 of the heat sink module 183 inaccordance with some embodiments. FIG. 2AB-(1) shows the second portion185 from a first side, and FIG. 2AB-(2) shows the second portion 185from a second side. As shown in FIG. 2AB, the second portion 185 issubstantially planar, and includes an array of through-holes atlocations that correspond to the array of laser diodes 1 in a laserarray module, each row or column of the through-holes are linked by arespective one of the linear grooves 121.

FIG. 2AZ illustrates another heat sink module 183′ that may be used inthe laser array modules disclosed herein, in accordance with someembodiments. The heat sink module 183′ is similar to the heat sinkmodule 183 shown in FIG. 2Z, except that heat sink module 183′ includesstraight through holes instead of stepped through-holes. In FIG. 2AZ,the heat sink module 183′ is integrated with a liquid cooling layer, andincludes a liquid cooling channel with an inlet 104 and an outlet 105.In some embodiments, the liquid cooling channel is a fluid channel or aseries of interconnected fluid chambers created within the body of theheat sink module, and is not necessarily in the form of a circular tubeembedded in the body of the heat sink module. The heat sink module 183′may replace the heat sink module 137′ or 139′ in the laser array modulein some embodiments.

FIG. 2AZ-(1) shows a perspective view of the heat sink module 183′ fromabove, and FIG. 2AZ-(2) shows a perspective view of the heat sink module183′ from below. As shown in FIG. 2AZ, the heat sink module 183′includes a first portion 184′ and a second portion 185 that are adheredtogether to form an enclosure in which a cooling liquid may circulate tocool the heat sink module 183. The inlet 104 and outlet 105 for thecooling liquid are opened in the body (side walls) of the first portion184, to allow a cooling liquid to enter and exit the enclosure (fluidchannel) created by the first portion 184′ and the second portion 185 ofthe heat sink module 183′.

As shown in FIG. 2AZ-(1), an array of through-holes (e.g., straightthrough-holes (to serve as the upper portions of straight through-holes120′) are opened in the first portion 184′ of the heat sink module 183′.As shown in FIG. 2AZ-(2), an array of through-holes (to serve as thelower portions of straight through-holes 120′) are opened. Eachthrough-hole in the first portion 184′ corresponds to a respectivethrough-hole in the second portion 185, and the two through-holes havethe same lateral position in their respective portions. In addition, asshown in FIG. 2AZ-(2), linear grooves 121 are created in the surface ofthe second portion 185 to each link a respective row or column ofthrough-holes in the second portion.

FIG. 2BA shows more details of the first portion 184′ of the heat sinkmodule 183′, in accordance with some embodiments. FIG. 2BA-(1) shows aperspective view of the first portion 184′ from a first side, and FIG.2BA-(2) shows a perspective view of the first portion 184′ from a secondside. As shown in FIG. 2BA-(1), the inside of the first portion 184′ arehollowed out leaving only solid materials around locations of thethrough holes (serving as straight through-holes 120′). For example, insome embodiments, the inside of the first portion is hollowed out,leaving a shell, and a plurality of islands and protrusions of solidmaterials attached to the shell. On each of the islands or protrusions,there are one or more straight through-holes (e.g., a row or column ofstraight through-holes from the array of straight through-holes servingas straight through-holes 120′). In addition, an inlet 104 and an outlet105 are created in the side walls of the shell, allowing a cooling fluidto enter into and exit the hollowed interior region within the firstportion 184.

As a person skilled in the art would appreciate, although the laserdiodes and array pattern shown in each of laser array modules disclosedherein appear to be identical, characteristics of individual laserdiodes (e.g., operating frequency, power, type, etc.) may be differentfor adaption in various applications. Furthermore, not all through-holes(e.g., stepped through-holes 120 or straight through-holes 120′) in aparticular array need to be implemented for a particular application, ifa laser light source (e.g., the laser diode 1) is not needed at thelocations of particular stepped through holes.

FIG. 2AC illustrates another heat sink module 187 that is integratedwith a cooling module without use of a cooling liquid, in accordancewith some embodiments. As shown in FIG. 2AC, the heat sink module 187includes a first portion 188 that includes an array of stepped throughholes 120 for accommodating an array of laser diodes 1 of the laserarray module, and a second portion 189 of dissipating heat collectedfrom the first portion 188. FIG. 2AC-(1) shows a perspective view of theheat sink module 187 from above, and FIG. 2AC-(2) shows a perspectiveview of the heat sink module 187 from below.

In the heat sink module 187, a plurality of heat conductive rods 190(e.g., copper rods or other metal rods) are inserted into the firstportion 188 of the heat sink module 187 on one end, and inserted into aheat exchanger 189 on the other end. The plurality of heat conductiverods 190 are positioned within the first portion 188 in a manner that donot touch or pass through the array of stepped through-holes 120 in thefirst portion 188, but are sufficiently close to the steppedthrough-holes 120 so as to efficiently extract heat from the steppedthrough-holes 120. On the back side of the first portion 188, aplurality of linear grooves 121 are created, each linking a respectiverow or column of stepped through-holes 120.

The heat sink module 187 shown in FIG. 2AC replaces the heat sink module(e.g., heat sink module 137 or 139) in a laser array module disclosedherein, in accordance with some embodiments. In essence, the firstportion of the heat sink module 187 is used to accommodate thecomponents of the laser array module, except for the liquid coolingtube, and the second portion 189 of the heat sink module 187 serves todissipate heat and replaces the liquid cooling tube/liquid cooling layerof the laser array module.

FIG. 2BB illustrates another heat sink module 187′ that is similar tothe heat sink module 187 in FIG. 2AC, in accordance with someembodiments, except that the heat sink module 187′ includes a firstportion 188′ with straight through-holes 120′ instead of a first portion188 with stepped through-holes 120. The heat sink module 187′ shown inFIG. 2BB can replace the heat sink module (e.g., heat sink module 137′or 139′) in a laser array module disclosed herein, in accordance withsome embodiments. In essence, the first portion of the heat sink module187′ is used to accommodate the components of the laser array module,except for the liquid cooling tube, and the second portion 189 of theheat sink module 187′ serves to dissipate heat and replaces the liquidcooling tube/liquid cooling layer of the laser array module.

FIG. 2AD illustrates another heat sink module 191 in accordance withsome embodiments. The heat sink module 191 utilizes liquid coolingwithin an enclosure created within the heat sink module 191. In someembodiments, the heat sink module 191 replaces other heat sink modules(e.g., heat sink module 137, 139, 147, 149, 161, 162, or 166, etc.) usedin the laser array modules disclosed herein.

FIG. 2AD-(1) shows a perspective view of the heat sink module 191 fromabove, and FIG. 2AD-(2) shows a perspective view of the heat sink module191 from below. As shown in FIG. 2AD, the heat sink module 191 is formedby a first portion 192, and a second portion 193 that are adheredtogether to create an enclosure in which a cooling fluid may circulate.The cooling liquid can enter the enclosure from an inlet 104, and exitthe enclosure from the outlet 105 created on the side wall(s) of theenclosure.

As shown in FIG. 2AD-(1), the first portion 192 of the heat sink module191 includes an array of through-holes at locations corresponding to thelocations of the array of laser diodes 1 in the laser array module.Within each of the through-holes 196 (see FIG. 2AE), a heat sink element194 is inserted. The heat sink element 194 includes a steppedthrough-hole 198 (See FIGS. 2AF-(2) and 2AF-(3)) that serves as thestepped through-hole 120 for accommodating a respective laser diode 1.As shown in FIG. 2AD-(2), the second portion 193 of the heat sink module191 includes an array of through holes 197 (see FIG. 2AF-(1)), and thelower portions of the heat sink elements 194 are inserted intorespective through-holes 197 in the second portion 193.

FIG. 2AE illustrates the structure of the first portion 192 of the heatsink module 191 in accordance with some embodiments. FIG. 2AE-(1) showsthe first portion 192 from a first side and FIG. 2AE-(2) shows the firstportion 192 from the opposite side.

As shown in FIG. 2AE-(1), the inside of the first portion 192 of theheat sink module 191 includes a hollowed out space that serves as afluid channel 195 for transporting a cooling liquid from an inlet 104 toan outlet 105 on the side wall(s) of the first portion 192. In someembodiments, the fluid channel created within the first portion 192includes a series of interconnected linear channels that run along therows or columns of the through-holes 196, as shown in FIG. 2AE-(1). Thelocations of the through-holes 196 in the first portion 192 of the heatsink module 191 correspond to the locations of the array of laser diodes1 in the laser array module.

FIG. 2AF-(1) shows the second portion 193 of the heat sink module 191 inaccordance with some embodiments. As shown in FIG. 2AF-(1), the secondportion 193 of the heat sink module 191 is a substantially planar bodywith an array of through-holes 197 created at locations that correspondto the array of laser diodes 1 in the laser array module.

FIGS. 2AF-(2) and 2AF-(3) illustrate the heat sink element 194 inaccordance with some embodiments. FIG. 2AF-(2) shows a perspective viewof the heat sink element 194 from one end, and FIG. 2AF-(3) shows aperspective view of the heat sink element 194 from the opposite end. Asshown in FIG. 2AF-(2), the heat sink element includes a steppedthrough-hole 198, where the stepped through-hole 198 serves as thestepped through-hole 120 to hold the laser diode in place. The steppedthrough-hole 198 includes an upper portion that is wider in diameter,and a lower portion that is narrower than the upper portion. When alaser diode 1 is inserted into the stepped through-hole 198, the supportplate of the laser diode rests on the stepped surface created betweenthe upper and lower portions of the stepped through-hole 198.

As shown in FIGS. 2AF-(2) and 2AF-(3), the heat sink element 194consists of a top cylindrical portion and a bottom cylindrical portionthat is narrower than the top cylindrical portion. A stepped surface iscreated between the top cylindrical portion and the bottom cylindricalportion, and when the heat sink element 194 is inserted into the firstportion 192 of the heat sink module 191, the external stepped surfacebetween the upper and lower portions of the heat sink element 191 restsagainst the top surface of first portion 192 around the through-hole196. When the lower portion of the heat sink element 194 is insertedinto the through-hole 197 in the second portion 193 of the heat sinkmodule, the tip of the lower portion of the heat sink element 194 isflush against the external surface of the second portion 193.

FIG. 2AG illustrates the assembled heat sink module 191 with a cutthrough view at the location of a heat sink element 194. As shown inFIG. 2AG, when the first portion 192 and the second portion 193 of theheat sink module are adhered together, a chamber is created between thefirst portion 192 and the second portion 193. The through-holes in thefirst portion and the through-holes in the second portion of the heatsink module 191 are at corresponding locations, such that an axisthrough a through-hole in the first portion 192 and its correspondingthrough-hole in the second portion 193 is perpendicular to the topsurface of the first portion 192 and the bottom surface of the secondportion 193. The islands and protrusions within the fluid chamber arearranged such that continuous flow of the cooling liquid from the inlet104 to the outlet 105 is realized. Furthermore, the cooling fluid wouldreach the region of every set of through-holes 120 (within heat sinkelements 194) when flowing through the fluid chamber.

FIG. 2AG further illustrates that, a heat sink element 194 is insertedin a respective set of through-holes in the first and second portions ofthe heat sink module 191. The side wall of the lower portion of the heatsink element 194, the top and side walls of the first portion 192 of theheat sink module 191, and the second portion 193 of the heat sink module191, together form a fully enclosed fluid channel through the heat sinkmodule 191. In some embodiments, the boundaries between differentcomponents of the heat sink module 191 are sealed such that leaking ofthe cooling fluid is prevented.

As shown in FIG. 2AG, the laser diode 1 is inserted into thethrough-hole 198 in the heat sink element 194 and the support plate ofthe laser diode 1 is rested on the stepped surface between the upper andlower portions of the heat sink element 194.

Although not shown in FIGS. 2AF-(1) and 2AG, the bottom surface of thesecond portion 193 includes linear grooves that each link a respectivesequence of through-holes 197, such that the conductive leads from thelaser diodes 1 within the stepped through-holes 198 of the heat sinkelements 194 can run within the linear grooves and eventually to thedriving circuit layers on the side(s) of the heat sink module 191.

FIG. 2BC illustrates another heat sink module 191′ in accordance withsome embodiments. The heat sink module 191′ is similar to the heat sinkmodule 191 shown in FIG. 2AD, except that the heat sink module 191′include straight through-holes instead of stepped through holes. Theheat sink module 191′ utilizes liquid cooling within an enclosurecreated within the heat sink module 191′. In some embodiments, the heatsink module 191′ replaces other heat sink modules (e.g., heat sinkmodule 137′, 139′, 147′, 149′, 161, 162, or 166, etc.) used in the laserarray modules disclosed herein.

FIG. 2BC-(1) shows a perspective view of the heat sink module 191′ fromabove, and FIG. 2BC-(2) shows a perspective view of the heat sink module191′ from below. As shown in FIG. 2BC, the heat sink module 191′ isformed by a first portion 192, and a second portion 193 that are adheredtogether to create an enclosure in which a cooling fluid may circulate.The cooling liquid can enter the enclosure from an inlet 104, and exitthe enclosure from the outlet 105 created on the side wall(s) of theenclosure. The portions 192 and 193 are the same as those shown in FIG.2AE.

As shown in FIG. 2BC-(1), the first portion 192 of the heat sink module191′ includes an array of through-holes at locations corresponding tothe locations of the array of laser diodes 1 in the laser array module.Within each of the through-holes 196 (see FIG. 2AE), a heat sink element194′ is inserted. The heat sink element 194′ includes a straightthrough-hole 198′ (See FIGS. 2BD-(1) and 2BD-(2)) that serves as thestraight through-hole 120′ for accommodating a respective laser diode 1.As shown in FIG. 2BC-(2), the second portion 193 of the heat sink module191′ includes an array of through holes 197 (see FIG. 2AF-(1)), and thelower portions of the heat sink elements 194′ are inserted intorespective through-holes 197 in the second portion 193.

FIGS. 2BD-(1) and 2BD-(2) illustrate the heat sink element 194′ inaccordance with some embodiments. FIG. 2BD-(1) shows a perspective viewof the heat sink element 194′ from one end, and FIG. 2BD-(2) shows aperspective view of the heat sink element 194′ from the opposite end. Asshown in FIG. 2BD-(1), the heat sink element includes a straightthrough-hole 198′, where the straight through-hole 198′ serves as thestraight through-hole 120′ to hold the laser diode in place. Thestraight through-hole 198′ includes an upper portion that is formed in aflat ring shaped collar of the element 194′, and a lower portion that isformed in a long tube portion of the element 194′. When a laser diode 1is inserted into the straight through-hole 198′, the support plate ofthe laser diode rests on the flat ring-shaped collar of the element194′.

As shown in FIGS. 2BD-(1) and 2BD-(2), the heat sink element 194′consists of a top cylindrical portion (a flat ring-shaped collar) and abottom cylindrical portion that is narrower than the top cylindricalportion. The center through-holes in the top portion and the bottomportion of the element 194′ have the same diameter; therefore, astraight through-hole is created between the top cylindrical portion andthe bottom cylindrical portion. When the heat sink element 194′ isinserted into the first portion 192 of the heat sink module 191′, theexternal stepped surface between the upper and lower portions of theheat sink element 191′ rests against the top surface of first portion192 around the through-hole 196. When the lower portion of the heat sinkelement 194′ is inserted into the through-hole 197 in the second portion193 of the heat sink module, the tip of the lower portion of the heatsink element 194′ is flush against the external surface of the secondportion 193.

FIG. 2BE illustrates the assembled heat sink module 191′ with a cutthrough view at the location of a heat sink element 194′. As shown inFIG. 2BE, when the first portion 192 and the second portion 193 of theheat sink module are adhered together, a chamber is created between thefirst portion 192 and the second portion 193. The through-holes in thefirst portion and the through-holes in the second portion of the heatsink module 191′ are at corresponding locations, such that an axisthrough a through-hole in the first portion 192 and its correspondingthrough-hole in the second portion 193 is perpendicular to the topsurface of the first portion 192 and the bottom surface of the secondportion 193. The islands and protrusions within the fluid chamber arearranged such that continuous flow of the cooling liquid from the inlet104 to the outlet 105 is realized. Furthermore, the cooling fluid wouldreach the region of every set of through-holes 120′ (within heat sinkelements 194′) when flowing through the fluid chamber.

FIG. 2BE further illustrates that, a heat sink element 194′ is insertedin a respective set of through-holes in the first and second portions ofthe heat sink module 191′. The side wall of the lower portion of theheat sink element 194′, the top and side walls of the first portion 192of the heat sink module 191, and the second portion 193 of the heat sinkmodule 191′, together form a fully enclosed fluid channel through theheat sink module 191′. In some embodiments, the boundaries betweendifferent components of the heat sink module 191′ are sealed such thatleaking of the cooling fluid is prevented.

As shown in FIG. 2BE, the laser diode 1 is inserted into thethrough-hole 198′ in the heat sink element 194′ and the support plate ofthe laser diode 1 is rested on the top surface of the flat collar of theheat sink element 194′.

Although not shown in FIGS. 2AF-(1) and 2BE, the bottom surface of thesecond portion 193 includes linear grooves that each link a respectivesequence of through-holes 197, such that the conductive leads from thelaser diodes 1 within the through-holes 198′ of the heat sink elements194′ can run within the linear grooves and eventually to the drivingcircuit layers on the side(s) of the heat sink module 191′.

Other details of the heat sink module and its functions and positions inthe laser array module are provided in other parts of thisspecification, and are not repeated here.

As disclosed herein, a system (e.g., a laser array module, or apartially assembled laser array module) includes at least a heat sinkmodule (e.g., any of heat sink modules 111, 137, 139, 147, 161, 166,183, 187, and 191, and various variations thereof as described herein)and a driving circuit module.

The heat sink module includes a respective top surface, a respectivebottom surface opposite to the respective top surface of the heat sinkmodule, and a plurality of first stepped through-holes (e.g., steppedthrough-holes 120) linking the respective top surface and the respectivebottom surface of the heat sink module. Each first stepped through-holehas a respective cylindrical upper portion and a respective cylindricallower portion that is narrower than the respective cylindrical upperportion of said each first stepped through-hole, e.g., as shown in FIG.2E. The respective cylindrical upper portion and the respectivecylindrical lower portion of said each first stepped through-hole (e.g.,stepped through-hole 120) are joined by a respective first ring-shapedsurface that is substantially perpendicular to the respectivecylindrical upper and lower portions of said each first steppedthrough-hole, e.g., as shown in FIG. 2E. The respective bottom surfaceof heat sink module includes a plurality of grooves (e.g., grooves 121).Each groove passes through the respective lower portions of a respectivesequence of first stepped through-holes (e.g., stepped through-holes120) among the plurality of first stepped through-holes in the heat-sinkmodule, e.g., as shown in FIG. 2E-(2).

The driving circuit module includes a plurality of conductive leadconnectors (e.g., conductive lead connectors 114, 116), and one or moreelectrical driving surfaces (e.g., driving circuit layers 118, 138) thatare disposed substantially perpendicular to the respective top andbottom surfaces of the heat sink module (e.g., any of heat sink module111, 137, 139, 147, 161, 166, 183, 187, and 191, etc.), e.g., as shownin FIGS. 2B-2C, 2L-2M, 2R, 2T, and 2W.

Each conductive lead connector (e.g., conductive lead connectors 114,116) lies at least partially within a respective one of the plurality ofgrooves (e.g., grooves 121) in the respective bottom surface of the heatsink module. The plurality of conductive lead connectors include a setof internal lead connectors (e.g., U-shaped conductive lead connectors114) and a set of external lead connectors (e.g., L-shaped conductivelead connectors 116). Each of the set of internal lead connectors linksat least two of the first stepped through-holes (e.g., steppedthrough-holes 120) in the respective sequence of first steppedthrough-holes passed by the respective one of the plurality of groovesin the respective bottom surface of the heat sink module, e.g., as shownin 2H, 2J, 2K, 2L, 2Q, 2U, and 2W, etc.

Each of the set of external lead connectors (e.g., L-shaped conductivelead connectors 116) links at least one of the first steppedthrough-holes in the respective sequence of first stepped through-holespassed by the respective one of the plurality of grooves (e.g., grooves121) in the respective bottom surface of the heat sink module to atleast one of the one or more electrical driving surfaces (e.g., drivingcircuit layer 118, 138) of the driving circuit module that are disposedsubstantially perpendicular to the respective top and bottom surfaces ofthe heat sink module, e.g., as shown in 2H, 2J, 2K, 2L, 2Q, 2U, and 2W,etc.

In some embodiments, the system (e.g., the laser array module) furtherincludes a plurality of laser diodes (e.g., an array of laser diodes 1).Each of the plurality of laser diodes is disposed in a respective one ofthe plurality of first stepped through-holes in the heat sink module.Each laser diode includes a respective laser diode body (e.g., laserdiode body 3), a respective set of conductive leads (e.g., conductiveleads 4), and a respective conductive support plate (e.g., support plate2) disposed between the respective laser diode body and the respectiveset of conductive leads of said each laser diode, e.g., as shown in FIG.2A.

The respective conductive support plate (e.g., support plate 2) of eachlaser diode is disposed at least partially within the respectivecylindrical upper portion of the respective one of the plurality offirst stepped through-holes (e.g., stepped through-holes 120) in theheat sink module, and is supported by the respective first ring-shapedsurface joining the respective cylindrical upper and lower portions ofthe respective one of the plurality of first stepped through-holes,e.g., as shown in FIGS. 2H, 2U, and 2W.

The respective set of conductive leads of each laser diode are disposedwithin the respective cylindrical lower portion of the respective one ofthe plurality of first stepped through-holes in the heat sink module,e.g., as shown in FIGS. 2H, 2U, and 2W.

In some embodiments, the driving circuit module includes a respectiveinsulation tube (e.g., insulator tube 112) disposed within therespective cylindrical lower portion of each first stepped through-hole(e.g., stepped through-hole 120), e.g., as shown in FIGS. 2H, 2U, and2W.

In some embodiments, each internal lead connector includes a U-shapedconductor (e.g., U-shaped conductive lead connector 114) with a firstarm and a second arm connected by a linear body. Each of the first andsecond arms of the U-shaped conductor is disposed within a respectiveone of the two first stepped through-holes connected by the internallead connector, and the linear body is disposed within the respectivegroove that passes through the two first stepped through-holes, e.g., asshown in FIGS. 2F, 2H, 2U, and 2W.

In some embodiments, the respective set of conductive leads of therespective laser diode disposed include a respective cathode lead, arespective anode lead, and optionally, a respective ground lead, andwherein each U-shaped conductor connects the respective cathode lead ofone laser diode to the respective anode lead of another laser diodealong the plurality of laser diodes.

In some embodiments, each external lead connector includes an L-shapedconductor (e.g., L-shaped conductive lead connector 116) with a firstleg and a second leg, wherein first leg of the L-shaped conductor isdisposed within a respective first stepped through-hole and the secondleg is disposed within the respective groove that passes through therespective first stepped through-hole and conductively connected to oneof the one or more electrical driving surfaces of the driving circuitmodule, e.g., as shown in FIGS. 2F, 2H, 2U, and 2W.

In some embodiments, each L-shaped conductor connects the respectivecathode lead or anode lead of one laser diode to one of the one or moreelectrical driving surfaces of the driving circuit module, e.g., asshown in FIGS. 2F, 2H, 2U, and 2W.

In some embodiments, the system further includes a cooling module (e.g.,cooling module 102 or a cooling module integrated with the heat sinkmodule). In some embodiments, the cooling module (e.g., cooling module189) includes a plurality of cooling rods (e.g., rods 190) that aredisposed between the top and bottom surfaces of the heat sink module(e.g., first portion 188 of heat sink module 187), and includes a heatdissipater (e.g., second portion 189 of the heat sink module 187) thatis connected to the plurality of cooling rods and disposed outside ofthe heat sink module (e.g., the first portion 188 of the heat sinkmodule 187), e.g., as shown in FIG. 2AC.

In some embodiments, the heat sink module includes a plurality ofinterconnected channels between the top and bottom surfaces of the heatsink module, e.g., as shown in FIGS. 2AA and 2AE, etc. The plurality ofinterconnected channels are configured to transport a cooling liquidbetween an inlet and an outlet, and wherein the plurality of firststepped through-holes (e.g., stepped through-holes 120) are separatedfrom the cooling liquid by respective metal tube (e.g., heat sinkelement 194) connecting the top and bottom surfaces of the heat sinkmodule (e.g., heat sink module 191), and inner surfaces of plurality offirst stepped through-holes comprises inner surfaces of the metal tubes(e.g., heat sink element 194), e.g., as shown in FIG. 2AG.

In some embodiments, the heat sink module includes a plurality ofinterconnected channels between the top and bottom surfaces of the heatsink module, wherein the plurality of interconnected channels areconfigured to transport a cooling liquid between an inlet and an outlet,and wherein the plurality of first stepped through-holes exist withinrows of solid material between the top and bottom surfaces of the heatsink module (e.g., as shown in FIG. 2AA-(1)).

In some embodiments, the system further includes a cooling tube (e.g.,cooling tube 103) disposed between the top and bottom surfaces of theheat sink module for transporting a cooling liquid between the top andbottom surfaces of the heat sink module, e.g., as shown in FIGS. 2B, 2L,2N, 2O, 2P, 2Q, 2R, 2S, 2T, and 2V, etc.

In some embodiments, the heat sink module includes a plurality ofchannels that run parallel to the plurality of grooves in the respectivebottom surface of the heat sink module, and wherein the cooling tubeincludes a plurality of parallel segments that are disposed within theplurality of channels, and a plurality of turning segments eachconnecting a respective pair of adjacent parallel segments of thecooling tube, e.g., as shown in FIGS. 2B, 2L, 2N, 2O, 2P, 2Q, 2R, 2S,2T, and 2V, etc.

In some embodiments, the plurality of channels are open channels in thetop surface of the heat sink module, e.g., as shown in FIGS. 2O, 2P, and2Q, etc.

In some embodiments, the plurality of channels are open channels in thebottom surface of the heat sink module, e.g., as shown in FIGS. 2B, 2L,and 2N, etc.

In some embodiments, the plurality of channels are internal channelsdisposed between the top and bottom surfaces of the heat sink module,e.g., as shown in FIGS. 2AA and 2AE, etc.

In some embodiments, the cooling tube (e.g., cooling tube 103) passesthrough at least one of the one or more electrical driving surfaces(e.g., driving circuit layer 138) that are disposed substantiallyperpendicular to the respective top and bottom surfaces of the heat sinkmodule, e.g., as shown in FIG. 2L.

In some embodiments, the cooling tube (e.g., cooling tube 103) does notpass through the one or more electrical driving surfaces (e.g., drivingcircuit layer 118) that are disposed substantially perpendicular to therespective top and bottom surfaces of the heat sink module, e.g., asshown in FIGS. 2B and 2R, etc.

In some embodiments, the system further includes a cooling module. Thecooling module includes a respective first surface, a respective secondsurface opposite to the respective first surface of the cooling module,and one or more cooling channels embedded between the respective firstsurface and the respective second surface of the cooling module. Forexample, the cooling module can be integrated into the heat sink module,as shown in FIGS. 2AA and 2AG. In some embodiments, the respective firstsurface of the cooling module is disposed next to the heat sink moduleand is in thermal contact with the bottom surface of the heat sinkmodule, e.g., when the cooling module is a separate layer from the heatsink module.

In some embodiments, a cooling tube is disposed between the first andsecond surfaces of the cooling module (e.g., cooling module 102) fortransporting a cooling liquid between the first and second surfaces ofthe heat sink module.

In some embodiments, the one or more cooling channels include aplurality of channels that run parallel to the plurality of grooves inthe respective bottom surface of the heat sink module, and the coolingtube includes a plurality of parallel segments that are disposed withinthe plurality of channels, and a plurality of turning segments eachconnecting a respective pair of adjacent parallel segments of thecooling tube, e.g., as shown in FIG. 2L.

In some embodiments, the plurality of channels are open channels in thetop surface of the cooling module. In some embodiments, the plurality ofchannels are open channels in the bottom surface of the cooling module.In some embodiments, the plurality of channels are internal channelsdisposed between the top and bottom surfaces of the cooling module.

In some embodiments, the system further includes a lens support module(e.g., the lens substrate layer 110). The lens support module includes arespective top surface, a respective bottom surface opposite to therespective top surface of the lens support module, and a plurality ofsecond stepped through-holes (e.g., stepped through-holes 119) linkingthe respective top surface and the respective bottom surface of the lenssupport module (e.g., the lens substrate layer 110), e.g., as shown inFIG. 2D. Each second stepped through-hole (e.g., stepped through-hole119) has a respective cylindrical upper portion and a respectivecylindrical lower portion that is narrower than the respectivecylindrical upper portion of said each second stepped through-hole,e.g., as shown in FIG. 2D. The respective cylindrical upper portion andthe respective cylindrical lower portion of said each second steppedthrough-hole are joined by a second ring-shaped surface that issubstantially perpendicular to the respective cylindrical upper andlower portions of said each second stepped through-hole. The respectivebottom surface of the lens support module is disposed on the respectivetop surface of the heat sink module, and the plurality of second steppedthrough-holes in the lens support module are aligned with the pluralityof first stepped through-holes in the heat sink module, e.g., as shownin FIGS. 2C, 2H, 2M, 2T, and 2V, etc.

In some embodiments, for each laser diode that has the respectiveconductive support plate thereof disposed at least partially within arespective one of the plurality of first stepped through-holes in theheat sink module: the respective laser diode body of said each laserdiode is disposed within the respective cylindrical lower portion of arespective one of the plurality of second stepped through-holes in thelens support module that is aligned with said respective one of theplurality of first stepped through-holes in the heat-sink module, e.g.,as shown in FIGS. 2H, 2U, and 2W, etc.

In some embodiments, a respective lens (e.g., lens 108) disposed atleast partially within the respective upper portion of each of theplurality of second stepped through-holes (e.g., stepped through-holes119) in the lens support module (e.g., lens substrate layer 110),wherein the respective lens is separated from the laser diode body inthe respective lower portion of said each second stepped through-hole bya respective gap, e.g., as shown in FIGS. 2H-(2), 2U, and 2W, etc.

In some embodiments, the lens support module comprises a top plate(e.g., top plate 176) and a bottom plate (e.g., bottom plate 178) bondedto the top plate. The top plate includes a plurality of first holes(e.g., through-holes 177) forming the respective cylindrical upperportions of the plurality of second stepped through-holes (e.g., steppedthrough-holes 119), and the bottom plate includes a plurality of secondholes (e.g., through-holes 179) forming the respective cylindrical lowerportions of the plurality of second stepped through-holes (e.g., steppedthrough-holes 119), e.g., as shown in FIG. 2X.

In some embodiments, the system further includes a lens module disposedon the top surface of the heat sink module, the lens module includes aplanar surface (e.g., substrate 181) with a plurality of lens domes(e.g., lens domes 180) on the planar surface, where the plurality oflens domes are aligned with the plurality of first stepped through holes(e.g., stepped through-holes 120) in the heat sink module, e.g., asillustrated in FIG. 2Y.

In some embodiments, a system (a double-sided laser array module, or apart thereof) includes a cooling module, a first heat sink module, afirst plurality of laser diodes, a first driving circuit module, asecond heat sink module, a second plurality of laser diodes, and asecond driving circuit module.

The cooling module has a first side and a second side opposite the firstside, and a cooling mechanism disposed between the first side and thesecond side of the cooling module. The first heat sink module has arespective top surface, a respective bottom surface opposite therespective top surface of the first heat sink module, and a respectiveplurality of first through-holes (e.g., stepped through-holes 120)linking the respective top and bottom surfaces of the first heat sinkmodule. The respective bottom surface of the heat sink module isdisposed next to the first side of the cooling module.

Each of the first plurality of laser diodes includes a respective diodebody, a respective set of conductive leads, and a respective supportplate between the respective diode body and the respective set ofconductive leads. Each of the first plurality of laser diodes isdisposed at least partially within a respective one of the respectiveplurality of first through-holes in the first heat sink module with therespective diode body disposed next to the respective top surface of thefirst heat sink module and the respective set of conductive leadsdisposed next to the bottom surface of the first heat sink module.

The first driving circuit module includes a respective plurality ofconductive lead connectors and respective one or more electrical drivingsurfaces. The respective one or more electrical driving surfaces of thefirst driving circuit module are disposed substantially perpendicular tothe respective top and bottom surfaces of the first heat sink module.The respective plurality of conductive lead connectors of the firstdriving circuit module connect the respective set of conductive leads ofthe first plurality of laser diodes to the respective one or moreelectrical driving surfaces of the first driving circuit module.

The second heat sink module has a respective top surface, a respectivebottom surface opposite the respective top surface of the second heatsink module, and a respective plurality of first through-holes (e.g.,stepped through-holes 120) linking the respective top and bottomsurfaces of the second heat sink module. The respective bottom surfaceof the heat sink module is disposed next to the second side of thecooling module.

Each of the second plurality of laser diodes includes a respective diodebody, a respective set of conductive leads, and a respective supportplate between the respective diode body and the respective set ofconductive leads. Each of the second plurality of laser diodes isdisposed at least partially within a respective one of the respectiveplurality of first through-holes (steppe through-holes 120) in thesecond heat sink module with the respective diode body disposed next tothe respective top surface of the second heat sink module and therespective set of conductive leads disposed next to the bottom surfaceof the second heat sink module.

The second driving circuit module includes a respective plurality ofconductive lead connectors and respective one or more electrical drivingsurfaces. The respective one or more electrical driving surfaces of thesecond driving circuit module are disposed substantially perpendicularto the respective top and bottom surfaces of the second heat sinkmodule. The respective plurality of conductive lead connectors of thesecond driving circuit module connect the respective set of conductiveleads of the second plurality of laser diodes to the respective one ormore electrical driving surfaces of the second driving circuit module.

In various embodiments, the system (e.g., the double-sided laser arraymodule 157, 162, 169, etc.) further includes the features described inother places in this specification.

In some embodiments, a system (e.g., a double-sided laser array module)includes a heat sink module (e.g., heat sink module 161, 166), a firstplurality of laser diodes, a second plurality of laser diodes, and adriving circuit module. The heat sink module has a respective topsurface, a respective bottom surface opposite the respective top surfaceof the heat sink module, a first plurality of first through-holes (e.g.,stepped through-holes 120-1) linking the respective top and bottomsurfaces of the heat sink module, a second plurality of secondthrough-holes (e.g., stepped through-holes 120-2) linking the respectivetop and bottom surfaces of the heat sink module. The first plurality offirst through-holes are arranged according to a first grid pattern andthe second plurality of first through-holes are arranged according to asecond grid pattern, and the first grid pattern and the second gridpattern are offset from each other, e.g., as shown in FIGS. 2T and 2V.

Each of the first plurality of laser diodes includes a respective diodebody, a respective set of conductive leads, and a respective supportplate between the respective diode body and the respective set ofconductive leads. Each of the first plurality of laser diodes isdisposed at least partially within a respective one of the firstplurality of first through-holes in the heat sink module with therespective diode body disposed next to the respective top surface of theheat sink module and the respective set of conductive leads disposednext to the respective bottom surface of the heat sink module.

Each of the second plurality of laser diodes includes a respective diodebody, a respective set of conductive leads, and a respective supportplate between the respective diode body and the respective set ofconductive leads, wherein each of the second plurality of laser diodesis disposed at least partially within a respective one of the secondplurality of first through-holes in the heat sink module with therespective diode body disposed next to the respective bottom surface ofthe heat sink module and the respective set of conductive leads disposednext to the respective top surface of the heat sink module.

The driving circuit module (e.g., the module including driving circuitlayers 118, conductive lead connectors 114 and 116, and insulator tubes112) includes a respective plurality of conductive lead connectors andrespective one or more electrical driving surfaces. The respective oneor more electrical driving surfaces of the driving circuit module aredisposed substantially perpendicular to the respective top and bottomsurfaces of the heat sink module. A first subset of conductive leadconnectors among the respective plurality of conductive lead connectorsof the driving circuit module connect the respective set of conductiveleads of the first plurality of laser diodes to the respective one ormore electrical driving surfaces of the first driving circuit module. Asecond subset of conductive lead connectors among the respectiveplurality of conductive lead connectors of the driving circuit moduleconnect the respective set of conductive leads of the second pluralityof laser diodes to the respective one or more electrical drivingsurfaces of the driving circuit module.

In various embodiments, the system (e.g., the double-sided laser arraymodule 162, 169, etc.) further includes the features described in otherplaces in this specification.

In some embodiments, instead of stepped through-holes, straightthrough-holes with no steps along the body of the through-holes are usedin the heat sink module and/or the lens array support module. Asdescribed in Figures AI-BC, the various combinations of steppedthrough-holes and straight through holes in the heat sink module and thelens array support substrate give rise to different configurations ofthe laser array module. In some embodiments, a system includes a heatsink module (e.g., any the heat sink modules shown in FIGS. 2B-2C, 2H,2L-2Q, and 2Z, 2AC, 2AD, 2AH, 2AI, 2AM-2AS, 2AT-2AX, 2AZ, 2BB, 2BC, andvariations thereof as described herein), and a driving circuit module.The heat sink module includes a respective top surface, a respectivebottom surface opposite to the respective top surface of the heat sinkmodule, and a plurality of first through-holes linking the respectivetop surface and the respective bottom surface of the heat sink module,and the respective bottom surface of heat sink module includes aplurality of grooves, wherein each groove passes through the respectivelower portions of a respective sequence of first through-holes among theplurality of first through-holes in the heat-sink module. The drivingcircuit module includes a plurality of conductive lead connectors, andone or more electrical driving surfaces that are disposed substantiallyperpendicular to the respective top and bottom surfaces of the heat sinkmodule, each conductive lead connector lies at least partially within arespective one of the plurality of grooves in the respective bottomsurface of the heat sink module, the plurality of conductive leadconnectors include a set of internal lead connectors and a set ofexternal lead connectors, each of the set of internal lead connectorslinks at least two of the first through-holes in the respective sequenceof first through-holes passed by the respective one of the plurality ofgrooves in the respective bottom surface of the heat sink module, andeach of the set of external lead connectors links at least one of thefirst through-holes in the respective sequence of first through-holespassed by the respective one of the plurality of grooves in therespective bottom surface of the heat sink module to at least one of theone or more electrical driving surfaces of the driving circuit modulethat are disposed substantially perpendicular to the respective top andbottom surfaces of the heat sink module.

In some embodiments, the system further includes a plurality of laserdiodes, where each of the plurality of laser diodes is disposed in arespective one of the plurality of first through-holes in the heat sinkmodule, said each laser diode includes a respective laser diode body, arespective set of conductive leads, and a respective conductive supportplate disposed between the respective laser diode body and therespective set of conductive leads of said each laser diode, therespective conductive support plate of said each laser diode is disposedon the top surface of the heat sink module, and the respective set ofconductive leads of said each laser diode are disposed within therespective one of the plurality of first through-holes in the heat sinkmodule.

In some embodiments, the driving circuit module includes a respectiveinsulation tube disposed within each first through-hole.

In some embodiments, each internal lead connector includes a U-shapedconductor with a first arm and a second arm connected by a linear body,wherein each of the first and second arms of the U-shaped conductor isdisposed within a respective one of the two first through-holesconnected by the internal lead connector, and the linear body isdisposed within the respective groove that passes through the two firstthrough-holes.

In some embodiments, the respective set of conductive leads of therespective laser diode disposed include a respective cathode lead and arespective anode lead, and wherein each U-shaped conductor connects therespective cathode lead of one laser diode to the respective anode leadof another laser diode along the plurality of laser diodes.

In some embodiments, each external lead connector includes an L-shapedconductor with a first leg and a second leg, wherein first leg of theL-shaped conductor is disposed within a respective first through-holeand the second leg is disposed within the respective groove that passesthrough the respective first through-hole and conductively connected toat least one of the one or more electrical driving surfaces of thedriving circuit module.

In some embodiments, each L-shaped conductor connects the respectivecathode lead or anode lead of one laser diode to at least one of the oneor more electrical driving surfaces of the driving circuit module.

In some embodiments, the system further includes a cooling module,wherein the cooling module includes a plurality of cooling rods that aredisposed between the top and bottom surfaces of the heat sink module,and includes a heat dissipater that is connected to the plurality ofcooling rods and disposed outside of the heat sink module.

In some embodiments, the heat sink module includes a plurality ofinterconnected channels between the top and bottom surfaces of the heatsink module, wherein the plurality of interconnected channels areconfigured to transport a cooling liquid between an inlet and an outlet,and wherein the plurality of first through-holes are separated from thecooling liquid by respective metal tube connecting the top and bottomsurfaces of the heat sink module, and inner surfaces of plurality offirst through-holes comprises inner surfaces of the metal tubes.

In some embodiments, the system includes a cooling tube disposed betweenthe top and bottom surfaces of the heat sink module for transporting acooling liquid between the top and bottom surfaces of the heat sinkmodule.

In some embodiments, the heat sink module includes a plurality ofchannels that run parallel to the plurality of grooves in the respectivebottom surface of the heat sink module, and wherein the cooling tubeincludes a plurality of parallel segments that are disposed within theplurality of channels, and a plurality of turning segments eachconnecting a respective pair of adjacent parallel segments of thecooling tube. In some embodiments, the plurality of channels are openchannels in the top surface of the heat sink module. In someembodiments, the plurality of channels are open channels in the bottomsurface of the heat sink module. In some embodiments, the plurality ofchannels are internal channels disposed between the top and bottomsurfaces of the heat sink module.

In some embodiments, the heat sink module includes a plurality ofinterconnected channels between the top and bottom surfaces of the heatsink module, wherein the plurality of interconnected channels areconfigured to transport a cooling liquid between an inlet and an outlet,and wherein the plurality of first through-holes exist within rows ofsolid material between the top and bottom surfaces of the heat sinkmodule.

In some embodiments, the cooling tube passes through at least one of theone or more electrical driving surfaces that are disposed substantiallyperpendicular to the respective top and bottom surfaces of the heat sinkmodule.

In some embodiments, the cooling tube does not pass through the one ormore electrical driving surfaces that are disposed substantiallyperpendicular to the respective top and bottom surfaces of the heat sinkmodule.

In some embodiments, the system includes a cooling module, wherein thecooling module includes a respective first surface, a respective secondsurface opposite to the respective first surface of the cooling module,and one or more cooling channels embedded between the respective firstsurface and the respective second surface of the cooling module, and therespective first surface of the cooling module is disposed next to theheat sink module and is in thermal contact with the bottom surface ofthe heat sink module. In some embodiments, the system includes a coolingtube disposed between the first and second surfaces of the coolingmodule for transporting a cooling liquid between the first and secondsurfaces of the heat sink module.

In some embodiments, the one or more cooling channels include aplurality of channels that run parallel to the plurality of grooves inthe respective bottom surface of the heat sink module, and wherein thecooling tube includes a plurality of parallel segments that are disposedwithin the plurality of channels, and a plurality of turning segmentseach connecting a respective pair of adjacent parallel segments of thecooling tube. In some embodiments, the plurality of channels are openchannels in the top surface of the cooling module. In some embodiments,the plurality of channels are open channels in the bottom surface of thecooling module. In some embodiments, the plurality of channels areinternal channels disposed between the top and bottom surfaces of thecooling module.

In some embodiments, the system includes a lens support module (e.g.,any the lens array substrate layers shown in FIGS. 2B-2D, 2H, 2L-2M, and2X-2Y, and variations thereof as described herein), wherein: the lenssupport module includes a respective top surface, a respective bottomsurface opposite to the respective top surface of the lens supportmodule, and a plurality of second through-holes linking the respectivetop surface and the respective bottom surface of the lens supportmodule, and the respective bottom surface of the lens support module isdisposed above the top surface of the heat sink module, and theplurality of second through-holes in the lens support module are alignedwith the plurality of first through-holes in the heat sink module.

In some embodiments, each laser diode has the respective laser diodebody thereof disposed at least partially within a respective lowerportion of a respective one of the plurality of second through-holes inthe lens support module.

In some embodiments, a respective lens disposed at least partiallywithin a respective upper portion of each of the plurality of secondthrough-holes in the lens support module, wherein the respective lens isseparated from the laser diode body in the respective lower portion ofsaid each second through-hole by a respective gap.

In some embodiments, the lens support module comprises a top plate and abottom plate bonded to the top plate, and wherein the top plate includesa plurality of first holes forming the respective cylindrical upperportions of the plurality of second through-holes, and the bottom plateincludes a plurality of second holes forming the respective cylindricallower portions of the plurality of second through-holes.

In some embodiments, the system includes a lens module disposed abovethe top surface of the heat sink module, the lens module includes aplanar surface with a plurality of lens domes on the planar surface,wherein the plurality of lens domes are aligned with the plurality offirst through holes in the heat sink module.

In some embodiments, the first through-holes are straight through-holeswith no steps along the respective bodies of the first through-holes. Insome embodiments, the second through-holes are straight through-holeswith no steps along the respective bodies of the second through-holes.In some embodiments, the diameter of each first through-hole is smallerthan the diameter of the support plate of a corresponding laser diodethat has its conductive leads disposed within said each firstthrough-hole. In some embodiments, the diameter of each secondthrough-hole is larger than the diameter of the support plate of saidcorresponding laser diode.

In the above detailed description, numerous specific details are setforth in order to provide a thorough understanding of the variousdescribed embodiments. However, it will be apparent to one of ordinaryskill in the art that the various described embodiments may be practicedwithout these specific details. In other instances, well-known methods,procedures, components, circuits, and networks have not been describedin detail so as not to unnecessarily obscure aspects of the embodiments.

It will also be understood that, although the terms first, second, etc.are, in some instances, used herein to describe various elements, theseelements should not be limited by these terms. These terms are only usedto distinguish one element from another. For example, a first lens arraycould be termed a second lens array, and, similarly, a second lens arraycould be termed a first array, without departing from the scope of thevarious described embodiments. The first lens array and the second lensarray are both lens arrays, but they are not the same lens arrays,unless the context clearly indicates otherwise.

The terminology used in the description of the various describedembodiments herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used in thedescription of the various described embodiments and the appendedclaims, the singular forms “a,” “an,” and “the” are intended to includethe plural forms as well, unless the context clearly indicatesotherwise. It will also be understood that the term “and/or” as usedherein refers to and encompasses any and all possible combinations ofone or more of the associated listed items. It will be furtherunderstood that the terms “includes,” “including,” “comprises,” and/or“comprising,” when used in this specification, specify the presence ofstated features, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, integers, steps, operations, elements, components,and/or groups thereof.

The use of terminology such as “front,” “back,” “top,” “bottom,” “left,”“right,” “over,” “above,” and “below” throughout the specification andclaims is for describing the relative positions of various components ofthe system(s) and relative positions of various parts of the variouscomponents described herein. Similarly, the use of any horizontal orvertical terms throughout the specification and claims is for describingthe relative orientations of various components of the system(s) and therelative orientations of various parts of the various componentsdescribed herein. Except where a relative orientation or position setforth below is explicitly stated in the description for a particularcomponent, system, or device, the use of such terminology does not implyany particular positions or orientations of the system, device,component or part(s) thereof, relative to (1) the direction of theEarth's gravitational force, (2) the Earth ground surface or groundplane, (3) a direction that the system(s), device(s), or particularcomponent(s) thereof may have in actual manufacturing, usage, ortransportation; or (4) a surface that the system(s), device(s), orparticular component(s) thereof may be disposed on during actualmanufacturing, usage, or transportation.

A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the inventions. Forexample, some processing steps may be carried out in a different order,modified, or omitted. The layout and configuration of the vibratingelements, electrodes, and electrical connections, may be varied.

The foregoing description has been provided with reference to specificembodiments. However, the illustrative discussions above are notintended to be exhaustive or to be limiting to the precise formsdisclosed. Many modifications and variations are possible in view of theabove teachings. The embodiments were chosen and described in order tobest explain the principles disclosed and their practical applications,to thereby enable others to best utilize the disclosure and variousembodiments with various modifications as are suited to the particularuse contemplated.

The invention claimed is:
 1. A system, comprising: a heat sink module,wherein: the heat sink module includes a respective top surface, arespective bottom surface opposite to the respective top surface of theheat sink module, and a plurality of first through-holes linking therespective top surface and the respective bottom surface of the heatsink module, and the respective bottom surface of the heat sink moduleincludes a plurality of grooves, wherein each groove passes throughrespective lower portions of a respective sequence of firstthrough-holes among the plurality of first through-holes in theheat-sink module; and a driving circuit module, wherein: the drivingcircuit module includes a plurality of conductive connectors, and one ormore electrical driving surfaces that are disposed substantiallyperpendicular to the respective top and bottom surfaces of the heat sinkmodule, each conductive connector lies at least partially within arespective one of the plurality of grooves in the respective bottomsurface of the heat sink module, the plurality of conductive connectorsinclude a set of internal connectors and a set of external connectors,each of the set of internal connectors links at least two of the firstthrough-holes in the respective sequence of first through-holes passedby the respective one of the plurality of grooves in the respectivebottom surface of the heat sink module, and each of the set of externalconnectors links at least one of the first through-holes in therespective sequence of first through-holes passed by the respective oneof the plurality of grooves in the respective bottom surface of the heatsink module to at least one of the one or more electrical drivingsurfaces of the driving circuit module that are disposed substantiallyperpendicular to the respective top and bottom surfaces of the heat sinkmodule.
 2. The system of claim 1, including: a plurality of laserdiodes, wherein: each of the plurality of laser diodes is disposed atleast partially within a respective one of the plurality of firstthrough-holes in the heat sink module, said each laser diode includes arespective laser diode body, a respective set of conductive leads, and arespective support plate disposed between the respective laser diodebody and the respective set of conductive leads of said each laserdiode, the respective set of conductive leads of said each laser diodeare disposed within the respective one of the plurality of firstthrough-holes in the heat sink module.
 3. The system of claim 2, whereinthe respective support plate of each laser diode is disposed on the topsurface of the heat sink module.
 4. The system of claim 3, wherein theplurality of first through-holes are straight through-holes with uniformwidths.
 5. The system of claim 2, wherein the respective support plateof each laser diode is disposed partially within a respective one of theplurality of first through-holes in the heat sink module.
 6. The systemof claim 2, further including: a lens support module, wherein: the lenssupport module includes a respective top surface, a respective bottomsurface opposite to the respective top surface of the lens supportmodule, and a plurality of second through-holes linking the respectivetop surface and the respective bottom surface of the lens supportmodule, and the respective bottom surface of the lens support module isdisposed above the top surface of the heat sink module, and theplurality of second through-holes in the lens support module are alignedwith the plurality of first through-holes in the heat sink module. 7.The system of claim 6, wherein, each laser diode has the respectivelaser diode body thereof disposed at least partially within a respectivelower portion of a respective one of the plurality of secondthrough-holes in the lens support module.
 8. The system of claim 6,wherein the lens support module comprises a top plate and a bottom platebonded to the top plate, and wherein the top plate includes a pluralityof first holes forming the respective cylindrical upper portions of theplurality of second through-holes, and the bottom plate includes aplurality of second holes forming the respective cylindrical lowerportions of the plurality of second through-holes.
 9. The system ofclaim 6, further including: a lens module disposed above the top surfaceof the heat sink module, the lens module includes a planar surface witha plurality of lens domes on the planar surface, wherein the pluralityof lens domes are aligned with the plurality of first through holes inthe heat sink module.
 10. The system of claim 1, wherein each internalconnector includes a U-shaped conductor with a first arm and a secondarm connected by a linear body, wherein each of the first and secondarms of the U-shaped conductor is disposed within a respective one ofthe two first through-holes connected by the internal connector, and thelinear body is disposed within the respective groove that passes throughthe two first through-holes.
 11. The system of claim 1, furtherincluding: a cooling module, wherein the cooling module includes aplurality of cooling rods that are disposed between the top and bottomsurfaces of the heat sink module, and includes a heat dissipater that isconnected to the plurality of cooling rods and disposed outside of theheat sink module.
 12. The system of claim 1, wherein the heat sinkmodule includes a plurality of interconnected channels between the topand bottom surfaces of the heat sink module, wherein the plurality ofinterconnected channels are configured to transport a cooling liquidbetween an inlet and an outlet, and wherein the plurality of firstthrough-holes are separated from the cooling liquid by respective metaltube connecting the top and bottom surfaces of the heat sink module, andinner surfaces of plurality of first through-holes comprises innersurfaces of the metal tubes.
 13. The system of claim 1, wherein the heatsink module includes a plurality of interconnected channels between thetop and bottom surfaces of the heat sink module, wherein the pluralityof interconnected channels are configured to transport a cooling liquidbetween an inlet and an outlet, and wherein the plurality of firstthrough-holes exist within rows of solid material between the top andbottom surfaces of the heat sink module.
 14. The system of claim 1,further including: a cooling tube disposed between the top and bottomsurfaces of the heat sink module for transporting a cooling liquidbetween the top and bottom surfaces of the heat sink module.
 15. Thesystem of claim 14, wherein the heat sink module includes a plurality ofchannels that run parallel to the plurality of grooves in the respectivebottom surface of the heat sink module, and wherein the cooling tubeincludes a plurality of parallel segments that are disposed within theplurality of channels, and a plurality of turning segments eachconnecting a respective pair of adjacent parallel segments of thecooling tube.
 16. The system of claim 15, wherein the plurality ofchannels are open channels in the top surface of the heat sink module.17. The system of claim 15, wherein the plurality of channels are openchannels in the bottom surface of the heat sink module.
 18. The systemof claim 15, wherein the plurality of channels are internal channelsdisposed between the top and bottom surfaces of the heat sink module.19. The system of claim 14, wherein the cooling tube passes through atleast one of the one or more electrical driving surfaces that aredisposed substantially perpendicular to the respective top and bottomsurfaces of the heat sink module.
 20. The system of claim 14, whereinthe cooling tube does not pass through the one or more electricaldriving surfaces that are disposed substantially perpendicular to therespective top and bottom surfaces of the heat sink module.
 21. Thesystem of claim 1, further including: a cooling module, wherein: thecooling module includes a respective first surface, a respective secondsurface opposite to the respective first surface of the cooling module,and one or more cooling channels embedded between the respective firstsurface and the respective second surface of the cooling module, and therespective first surface of the cooling module is disposed next to theheat sink module and is in thermal contact with the bottom surface ofthe heat sink module.
 22. The system of claim 21, further including: acooling tube disposed between the first and second surfaces of thecooling module for transporting a cooling liquid between the first andsecond surfaces of the heat sink module.